The Vascular Plants of Iowa

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• Iowa and Its Flora
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Artemisia abrotanurn
Rare southeast: Muscatine county 1892

Artemisia absinthium
Rare northwest: Sioux county

Botrychium matricariifolium
Rare northwest: Dickinson county and Osceola county

Alopecurus aequalis
Common in lakes area; infrequent to rare elsewhere

Arabis divaricarpa
Rare in northwest and north central

Argemone albiflora
Rare west central, east central and southeast: Iowa county 1927, Louisa county and Sac county 1923

Amaranthus albus
Rare northwest; frequent to common elsewhere

Amelanchier alnifolia
Rare northwest and north central: Dickinson county, Emmet county, Hancock county and Lyon county

Ailanthus altissima
Frequent in southern half, spreading from cultivation

Alyssum alyssoides
Rare west central, northwest and east central: Emmet county 1927, Dickinson county, Johnson county 1919 and Monona county 1932

Apios americana
Absent northwest; rare in Iowan Surface; frequent to common elsewhere

Asclepias amplexicaulis
Frequent east; rare to infrequent elsewhere

Apocynum androsaemifolium
Common northeast; rare northwest; infrequent elsewhere

Artemisia annua
Rare southeast and south central

Armoracia aquatica
Rare east central, southeast and southwest: Muscatine county 1894, Scott county pre-1900 and Union county 1882

Amelanchier arborea
Infrequent northeastern quarter; absent northwest; frequent elsewhere

Trifolium aureum
Rare west central, northwest and southeast: Guthrie county, Muscatine county 1895 and Palo Alto county 1935

Ambrosia artemisiifolia
Common throughout

Anthemis arvensis
Rare central: Poweshiek county and Webster county 1903

Anagallis arvensis
Rare central and east central: Johnson county, Scott county 1886 and Story county

Agalinis aspera
Frequent in Iowan Surface and southwest; infrequent northeast; rare northwest

Angelica atropurpurea
Rare north central and east

Anchusa azurea
Rare west central and northwest: Carroll County, Dickinson county 1928

Aster azureus
Frequent to common southeastern two-thirds

Abies balsamea
Rare northeast: Allamakee County, Clayton County, Howard county and Winneshiek county

Glyceria grandis
Infrequent to rare throughout

Ambrosia bidentata
Rare southeast and south central: Jefferson county, Monroe county 1949 and Van Buren county

Artemisia biennis
Infrequent to rare throughout

Aster brachyactis
Rare north central and in lakes area

Amphicarpaea bracteata
Frequent to common throughout

Acorus calamus
Frequent central and in lakes area; rare west and extreme northeast

Astragalus adsurgens
Rare to infrequent west and south; frequent to common elsewhere

Allium canadense
Frequent to common throughout

Astragalus canadensis
Common western half; infrequent to frequent eastern half

Anemone canadensis
Frequent extreme east and south central; common elsewhere

Arabis canadensis
Common in Paleozoic Plateau; infrequent to frequent elsewhere

Aquilegia canadensis
Frequent south central and southwest; common elsewhere

Amorpha canescens
Common throughout

Apocynum cannabinum
Frequent to common throughout

Asarum canodense
Common eastern two-thirds; frequent southwest; rare northwest

Anemone caroliniana
Frequent in Des Moines lobe; infrequent to rare elsewhere

Alopecurus carolinianus
Infrequent south; rare northwest and northeast

Allium cernuum
Rare in Paleozoic Plateau

Ammannia coccinea
Common southwest; infrequent to rare elsewhere; no records from Paleozoic Plateau

Ampelopsis cordata
Rare southeast and southwest: Fremont county 1898 and Lee county

Aster cordifolius
Common southwest; frequent eastern half

Anthemis cotula
Frequent to common throughout

Astragalus crassicarpus
Common northwest and north central; infrequent northeast, south central and southwest; rare or absent elsewh

Agropyron cristatum
Rare escape central and west; planted for erosion control

Aristida curtissii
Common extreme northwest; infrequent to rare elsewhere

Anemone cylindrica
Common northwestern half; infrequent to rare elsewhere

Aegilops cylindrica
Rare central, south central and southwest: Boone County, Decatur County, Mahaska county 1938 and Taylor county 1942

Aristida dichotoma
Infrequent southeast; rare southwest, and in northwest: Lyon county 1949

Aruncus dioicus
Rare east: Clinton County, Des Moines county, Dubuque county, Jackson county, Lee county and Muscatine county

Cypripedium calceolus
Infrequent to rare east

Botrychium campestre
Rare central, northwest, northeast and east central: Delaware County 1919, Dubuque county 1922, Emmet county 1927, Johnson county, Jones county and Webster county 1903

Arisaema dracontium
Rare to infrequent northeast; frequent south; rare in lakes area

Artemisia dracunculus
Infrequent to rare throughout

Arabis drummondii
Infrequent east; rare south central

Aster drummondii
Frequent southeast; infrequent to rare north and south central

Aster dumosus
Rare east and south central: Decatur County 1903, Delaware County, Johnson county, Louisa county and Marion county 1920

Arrhenatherum elatius
Rare escape from cultivation in central, northwest, east central and southwest: Dickinson county, Marshall county, Page county, Scott county and Story county

Asclepias engelmanniana
Rare west central and southwest: Monona county and Pottawattamie county

Aster ericoides
Frequent to common throughout

Agrimonia eupatoria
Rare central: Story county 1907

Asclepias exaltata
Frequent in Paleozoic Plateau; rare elsewhere

Cypripedium candidum
Rare northwest: Clay County 1936 and Palo Alto county 1936

Avena fatua
Rare throughout

Athyrium filix-femina
Rare northwest; frequent to common elsewhere

Astragalus flexuosus
Rare northwest: Lyon county

Agastache foeniculum
Rare central, northwest and northeast: Clay County, Clayton County 1933, Dickinson county, Emmet county, Lyon county and Story county 1948

Artemisia frigida
Rare northwest: Lyon county

Amorpha fruticosa
Frequent to common throughout most of state

Adlumia fungosa
Rare east central: Benton County 1910

Aster furcatus
Rare southeast and south central: Madison county 1917 and Muscatine county

Agalinis gattingeri
Rare central, east central, southeast and south central: Decatur County 1903, Henry county n.d., Jefferson county 1935, Jones county, Lee county, Muscatine county and Webster county 1908

Andropogon gerardii
Common throughout

Agrostis gigantea
Common throughout

Acer ginnala
Infrequent escape from cultivation

Agrostemma githago
Rare weed in eastern two-thirds; last collected in 1925

Arabis glabra
Rare northeast, extreme east and south central

Aesculus glabra
Common southeast and south central; infrequent southwest; infrequent escape from cultivation north central

Acalypha gracilens
Rare east: Benton County, Buchanan County, Jones county, Lee county, Muscatine county and Wapello county 1938

Corydalis curvisiliqua
Rare west central: Greene county

Aureolaria grandiflora
Frequent extreme east; rare southeast and south central

Amaranthus groecizans
Rare in Iowan Surface; frequent to common elsewhere

Agrimonia gryposepala
Infrequent southern half and north central; frequent to common elsewhere

Andropogon hallii
Rare west central and southeast: Louisa county, Muscatine county and Woodbury county

Aesculus hippocastanum
Occasional escape from cultivation throughout

Arabis hirsuta
Infrequent to rare throughout

Asclepias hirtella
Not reported central and west; infrequent to rare elsewhere

Amelanchier humilis
Frequent north central and in Paleozoic Plateau; rare in Iowan Surface

Amaranthus hybridus
Rare northeast and southwest; infrequent southeast

Aplectrum hyemale
Infrequent to rare central and east

Agrostis hyemalis
Frequent east; infrequent to rare west

Agrostis hyemalis
Frequent northern half; rare southeast; absent elsewh

Asclepias incarnata
Frequent to common throughout

Amelanchier interior
Frequent in Paleozoic Plateau; rare extreme east

Agropyron intermedium
Rare escape from experimental plantings in central and southeast: Keokuk county and Story county

Aster junciformis
Rare north

Arabis laevigata
Infrequent northeastern quarter; rare southeast

Aster laevis
Frequent to common throughout

Aster lanceolatus
Rare to infrequent throughout

Asclepias lanuginosa
Rare northern half and Muscatine county

Arctium lappa
Rare north central and southeast: Des Moines county and Floyd county

Aster lateriflorus
Common southeast; frequent northeast; infrequent southwest

Aster linariifolius
Rare east central and southeast: Clinton County, Louisa county 1927 and Muscatine county 1896

Aristida longespica
Rare southeast

Croton glandulosus
Infrequent southern half; rare northwest: Lyon county and Palo Alto county

Astragalus lotiflorus
Common northwest; rare north central and southwest

Artemisia ludoviciana
Frequent to common throughout

Arabis lyrata
Common in Paleozoic Plateau; infrequent to rare rest of northeast, east and south central

Aster macrophyllus
Rare northeast: Winneshiek county

Anaphalis margaritacea
Rare northeast and east central: Black Hawk County 1892, Clayton County 1924, Fayette county ca. 1897 and Linn county 1933

Euphorbia hexagona
Rare east central and south: Adams County 1899, Adair County, Clarke County, Decatur County, Scott county 1889 and Warren county

Aronia melanocarpa
Rare northeast: Winneshiek county

Argemone mexicana
Rare southeast: Henry county 1897 and Muscatine county 1896

Azolla mexicana
Common to infrequent along Mississippi River; rare east central and southwest: Benton County, Cedar County, Fremont county 1906, Johnson county and Linn county

Physalis ixocarpa
Common throughout

Arctium minus
Frequent to common throughout

Arabis missouriensis
Rare northeast: Allamakee County

Astragalus missouriensis
Rare west central and northwest: Plymouth county and Woodbury county

Adoxa moschatellina
Rare central, northeast and east central

Allium mutabile
Rare northeast: Black Hawk County

Amorpha nana
Rare central, north, and south central

Antennaria neglecta
Infrequent southwest; frequent to common elsewhere

Acer negundo
Common throughout

Agastache nepetoides
Frequent south central; infrequent to rare elsewhere

Aristida longespica
Common eastern two-thirds, except rare southeast

Aster novae-angliae
Frequent to common throughout

Aconitum noveboracense
Rare central, northeast and east central: Allamakee County, Clayton County, Delaware County, Dubuque county, Hardin county and Jackson county

Aralia nudicaulis
Frequent to common north central and northeast; infrequent to rare elsewhere

Aster oblongifolius
Common southwest; frequent to infrequent elsewhere

Androsace occidentalis
Frequent north central and extreme east; infrequent to rare elsewhere

Asparagus officinalis
Frequent to common escape from cultivation

Aristida oligantha
Common southern half; rare northern half

Aster ontarionis
Frequent to common throughout

Acalypha ostryifolia
Rare southwest: Fremont county 1940 and Pottawattamie county 1949

Asclepias ovalifolia
Rare to infrequent north

Actaea pachypoda
Frequent to common eastern half and central; rare southwest

Aster parviceps
Frequent to infrequent southwest; rare northeast

Agrimonia parviflora
Frequent southeast; infrequent south central

Atriplex patula
Infrequent to rare northwest, east and southern half

Agalinis paupercula
Infrequent to rare north central and east; rare southwest: Pottawattamie county 1898

Hepatica nobilis
Rare escape from cultivation in west central, northwest and northeast: Allamakee County, Monona county, Plymouth county and Woodbury county

Adiantum pedatum
Rare northwest; frequent north central; common elsewhere

Aureolaria pedicularia
Rare northeast: Allamakee County

Agrostis perennans
Frequent south; infrequent to rare north

Alliaria petiolata
Rare: scattered localities, rapidly increasing its range

Aster pilosus
Rare northern half; common southern half

Antennaria plantaginifolia
Rare to infrequent southwest; common elsewhere

Alisma plantago-aquatica
Common in most of state

Asplenium platyneuron
Infrequent southeast; rare northeast, east central and south central

Argemone polyanthemos
Rare northwest: Plymouth county

Allium porrum
Rare southwest: Mills county

Parietaria pensylvanica
Rare northwest: Clay County and Palo Alto county

Aster praealtus
Frequent to infrequent eastern half of state

Polygonum pensylvanicum
Rare northwest: Emmet county 1942

Alopecurus pratensis
Rare central and north central: Hancock county and Story county

Panicum philadelphicum
Rare to infrequent eastern two-thirds of state

Ambrosia psilostachya
Common southwest and in Loess Hills; infrequent to rare elsewhere

Aster pubentior
Rare central: Jasper county

Agrimonia pubescens
Infrequent northwest and north central; frequent to common elsewhere

Aster puniceus
Infrequent in Des Moines Lobe and in Iowan Surface; rare southeast and south central: Decatur County 1903 and Muscatine county 1927

Asclepias purpurascens
Infrequent to rare throughout

Agalinis purpurea
Absent southeast and south central; infrequent to rare elsewhere

Carex praegracilis
Rare northwest

Athyrium pycnocarpon
Rare east

Asclepias quadrifolia
Rare central and south central; infrequent southeast

Anemone quinquefolia
Common northeast and in Paleozoic Plateau; infrequent extreme east and central; rare southeast and south central

Aralia racemosa
Frequent eastern half; infrequent to rare western half

Bromus pubescens
Rare southeast: Henry county 1894

Agropyron repens
Common throughout

Aristida purpurea
Rare northern quarter of state

Amaranthus retroflexus
Frequent to common throughout

Asplenium rhizophyllum
Common east; absent northwest; rare elsewhere

Acalypha rhomboidea
Common east, north central and south central; infrequent elsewhere

Osmunda regalis
Rare south

Alcea rosea
Common throughout most of state

Atriplex rosea
Rare central, northwest and southwest: Cass County 1927, Emmet county 1932, Polk county 1911 and Sioux county 1931

Actaea rubra
Rare southeast and south central; frequent to common elsewhere

Acer rubrum
Rare northeast: Allamakee County; widely cultivationivated

Amaranthus rudis
Infrequent to frequent throughout

Alnus rugosa
Rare northeast

Armoracia rusticana
Rare escape from cultivation throughout

Acer saccharinum
Common throughout

Acer saccharum
Common east

Aster sagittifolius
Common southern half; frequent northeast; rare north central

Amelanchier sanguinea
Rare north, central and east central

Avena sativa
Infrequent escape from cultivation, not persisting

Aster schreberi
Rare east central and southeast: Muscatine county and Scott county 1932

Agastache scrophulariifolia
Common north central; infrequent to rare elsewhere

Aster sericeus
Common west; frequent to infrequent east

Aristolochia serpentaria
Rare southeast: Henry county, Lee county, and Muscatine county 1897

Arenaria serpyllifolia
Rare northwest: Emmet county 1929

Artemisia serrata
Rare eastern two-thirds

Arabis shortii
Infrequent to rare throughout

Aster shortii
Common northeast; infrequent southeast; rare north central

Apocynum sibiricum
Frequent to infrequent throughout

Agalinis skinneriana
Rare northeast and southeast: Allamakee County, Dubuque county and Muscatine county 1922

Agropyron smithii
Infrequent northeast and east central; frequent to common elsewhere

Asclepias speciosa
Infrequent to rare western half

Acer spicatum
Rare northeast: Allamakee County, Clayton County, Dubuque county and Winneshiek county

Amaranthus spinosus
Rare southeast: Keokuk county and Lee county 1925

Carex sparganioides
Frequent to common northwestern quarter; rare northeast

Asclepias stenophylla
Rare west central and northwest: Guthrie county, Plymouth county and Sioux county

Allium stellatum
Rare escape from golf greens

Agrimonia striata
Infrequent to rare throughout

Erigeron strigosus
Infrequent to rare throughout most of state; apparently absent northeast and east central

Asclepias syriaca
Common throughout

Agalinis tenuifolia
Infrequent northeast and southeast; rare northwest; common elsewhere

Athyrium thelypterioides
Infrequent to frequent east

Abutilon theophrasti
Common throughout

Anthemis tinctoria
Rare northeast: Clayton County 1929

Arctium tomentosum
Rare northwest: Emmet county 1923

Agropyron trachycaulum
Frequent to common north; infrequent to rare southeast and south central

Allium tricoccum
Frequent to common northeast; infrequent elsewhere

Ambrosia trifida
Common throughout

Asimina triloba
Rare east central, southeast and southwest: Clinton County, Des Moines county, Fremont county, Jackson county, Lee county, Louisa county, Taylor county and Van Buren county

Arisaema triphyllum
Common throughout

Amaranthus tuberculatus
Frequent to common southeast; infrequent north central and northeast; rare south central

Aristida tuberculosa
Infrequent to rare eastern quarter

Asclepias sullivantii
Infrequent to frequent throughout

Aster turbinellus
Rare southeast: Lee county

Aster umbellatus
Rare to infrequent throughout

Arctostaphylos uva-ursi
Rare northeast: Fayette county and Winneshiek county 1930

Asclepias verticillata
Common throughout

Allium vineale
Rare in east central and south, spreading rapidly

Anemone virginiana
Frequent south central; infrequent northwest; common elsewhere

Acalypha virginica
Common south; infrequent east; rare northwest

Andropogon virginicus
Rare southeast

Asclepias viridiflora
Frequent to common western half; infrequent to rare eastern half

Artemisia vulgaris
Rare northeast and east central: Delaware County, Scott county late 1800's

Anthyllis vulneraria
Rare central and north central: Story county and Wright county, last collected in 1935

Aster X amethystinus
Rare north central and east central: Butler County, Floyd county and Scott county

Apocynum X medium
Frequent southeast

Betula alleghaniensis
Rare central, north central and northeast: Allamakee County, Clayton County, Delaware County, Dubuque county, Fayette county, Hardin county, Mitchell county and Winneshiek county

Bidens aristosa
Rare central, east central and southeast: Des Moines county, Iowa county 1928, Jefferson county, Keokuk county, Muscatine county, Poweshiek county, Scott county and Washington county

Boltonia asteroides
Common north central; infrequent to frequent south, also Dickinson county

Baptisia australis
Rare northwest, south central and southwest: Adair County, Decatur County and Page county

Bidens bipinnata
Rare southeast: Lee county and Louisa county

Baptisia bracteata
Infrequent to frequent throughout much of state; rare northwest and extreme east

Besseya bullii
Rare north and east

Scirpus acutus
Rare west; discovered in 1982

Brassica campestris
Rare escape from cultivation

Bulbostylis capillaris
Rare to infrequent east

Bidens cernua
Frequent to common throughout

Belamcanda chinensis
Rare escape from cultivation

Blephilia ciliata
Rare southeast and south central: Appanoose County 1902, Davis County 1939, Des Moines county, Henry county n.d., Jefferson county 1934, Lee county and Van Buren county

Bromus ciliatus
Rare in northeastern quarter

Bromus commutatus
Infrequent throughout much of state

Carex amphibola
Common southeast; rare to frequent elsewhereere

Bidens coronata
Common southwest; frequent to infrequent elsewhere

Bouteloua curtipendula
Frequent to common throughout

Boehmeria cylindrica
Frequent to common south central and extreme east; infrequent to rare elsewhere

Buchloe dactyloides
Rare, native in west central and northwest: Lyon county, Plymouth county and Woodbury county, introduced elsewh

Bidens discoidea
Rare eastern quarter

Sagittaria brevirostra
Rare eastern half

Cypripedium calceolus
Infrequent eastern half

Berula erecta
Rare northwest and southwest: Cherokee County, Clay County, Dickinson county, Emmet county 1949, Palo Alto county 1936 and Pottawattamie county 1853

Brachyelytrum erectum
Frequent to common east; rare elsewhere

Brickellia eupatorioides
Frequent to common throughout

Bidens frondosa
Common north central and in lakes area; rare to infrequent elsewhere

Bouteloua gracilis
Frequent west

Blephilia hirsuta
Not reported from northwest; rare north central and in Iowan Surface; infrequent elsewhere

Bouteloua hirsuta
Frequent to infrequent west; rare elsewhere

Berteroa incana
Rare northeast and south central; frequent to infrequent elsewhere

Bromus inermis
Common throughout

Aster falcatus
Frequent to common throughout

Brassica juncea
Common southwest; infrequent elsewhere

Brassica Kaber
Rare southwest: Page county

Bromus kalmii
Frequent in Paleozoic Plateau; rare elsewhere in east

Baptisia lactea
Infrequent to frequent throughout much of state; rare northwest and extreme northeast

Bromus latiglumis
Infrequent to frequent east; rare southwest

Ceanothus herbaceus
Rare northeast: Allamakee County

Bromus mollis
Rare central and northeast: Black Hawk County 1896 and Webster county n.d.

Botrychium multifidum
Rare northeast: Allamakee County, Buchanan County, Clayton County, Dubuque county, Fayette county 1893, Linn county and Winneshiek county

Brassica napus
Rare escape from cultivation

Brassica nigra
Absent northwest; frequent to common elsewhere

Betula nigra
Common east; infrequent to frequent central; rare southwest

Ballota nigra
Rare southwest: Mills county

Brassica oleracea
Rare escape from cultivation

Betula papyrifera
Common in Paleozoic Plateau; rare in Iowan Surface, and in central and east central: Hardin county, Johnson county

Bidens polylepis
Common southwest; rare northeast; infrequent elsewhere

Polygala polygama
Frequent to infrequent throughout

Aster praealtus
Rare north central and northeast: Allamakee County, Black Hawk County, Bremer County, Chickasaw County, Clayton County, Howard county and Mitchell county

Lycopodium porophilum
Rare northeast: Chickasaw County

Bacopa rotundifolia
Infrequent southeast and south central; rare northwest and northeast

Carex rosea
Rare in scattered localities throughout

Bromus secalinus
Infrequent southeast and southwest; rare elsewhere

Paspalum setaceum
Rare central, northeast and east central: Black Hawk County, Linn county and Marshall county

Beckmannia syzigachne
Rare northwest: Clay County, Dickinson county, Emmet county, Lyon county, O'Brien county, Osceola county and Palo Alto county

Bromus tectorum
Frequent to common throughout

Berberis thunbergii
Rare escape from cultivation

Baptisia tinctoria
Rare south central: Madison county 1917

Bidens tripartita
Common southeast; rare to infrequent elsewhere

Botrychium virginianum
Common east; frequent west

Berberis vulgaris
Rare escape from cultivation

Elymus villosus
Rare northwest; common elsewhere

Bidens vulgata
Rare northwest and northeast; frequent to common elsewhere

Carduus acanthoides
Rare southern half; infrequent northwest

Lycopodium digitatum
Infrequent to rare southwestern two-thirds

Carex aggregata
Rare central, northeast and southwest: Allamakee County, Clayton County, Page county and Story county

Chenopodium album
Frequent in Paleozoic Plateau; common elsewhere

Carex albursina
Frequent to common east; rare to infrequent elsewhere

Callirhoe alcaeoides
Rare northwest and southwest: Dickinson county, Page county

Carex alopecoidea
Rare in lakes area, southeast and south central

Circaea alpina
Frequent in Paleozoic Plateau; rare southeast: Muscatine county 1896

X Elyhordeum iowense
Frequent to common northeastern two-thirds; rare south; absent northwest and southwest

Cirsium altissimum
Rare northeast; infrequent northwest; common elsewhere

Consolida ambigua
Rare escape from cultivation south

Chenopodium ambrosioides
Rare southern half and north central

Conopholis americana
Rare northeast: Allamakee County

Campanula americana
Common throughout

Corylus americana
Infrequent northwest; common elsewhere

Ceanothus americanus
Frequent northwest; infrequent south central; common elsewhere

Solatium americanum
Common in northeastern quarter; infrequent throughout most of state

Lycium halimifolium
Infrequent northern half; infrequent to common southern half

Carex annectens
Rare to infrequent southwest three-quarters

Campanula aparinoides
Frequent north central; rare to absent elsewhere

Carex aquatilis
Rare northwest and central

Caragana arborescens
Rare northeast: Dubuque county

Cyperus aristatus
Frequent north central; infrequent southwestern half; rare east

Carex artitecta
Rare southwest, southeast and in lakes area

Cinna arundinacea
Frequent to infrequent throughout most of state

Cirsium arvense
Frequent to common throughout

Cerastium arvense
Rare northeast and east central: Allamakee County, Clayton County, Delaware County, Dubuque county, Fayette county, Jackson county, Howard county and Winneshiek county

Convolvulus arvensis
Rare southeast; frequent to common elsewhere

Nasturtium officinale
Rare north

Carex atherodes
Frequent to common central and in lakes area; rare to infrequent elsewhere

Cacalia atriplicifolia
Infrequent to frequent southern half

Cycloloma atriplicifolium
Frequent to common southeast; infrequent extreme east and south central; rare elsewhere

Corydalis aurea
Rare in scattered localities throughout

Barbarea vulgaris
Rare northwest and northeast: Allamakee County, Dubuque county, Emmet county and Winneshiek county

Carex bebbii
Infrequent northern half; rare southern half

Chenopodium berlandieri
Common north central; rare east central and southeast: Johnson county and Henry county

Carex bicknellii
Frequent west three-quarters; rare e

Catalpa bignonioides
Rare escape from cultivation

Carex blanda
Common throughout

Chenopodium botrys
Infrequent central; rare northeast and southeast

Carex brevior
Common west and southeast; frequent elsewh

Cystopteris bulbifera
Rare central; frequent to common east

Cicuta bulbifera
Frequent in lakes area; rare eastern half

Cardamine bulbosa
Common northeast; rare west; infrequent elsewhere

Capsella bursa-pastoris
Common throughout

Chenopodium bushianum
Common north central; rare extreme east

Callirhoe bushii
Rare southwest: Page county

Carex bushii
Rare southeast and southwest: Davis County 1939, Lee county, Page county and Wapello county 1939

Carex buxbaumii
Rare to infrequent e three-quarters

Betula pumila X Betula nigra
Rare northeast: Buchanan County and Chickasaw County

Cyperus acuminatus
Infrequent to rare eastern half; rare and scattered western half

Centaurea calcitrapa
Rare central: Story county

Crataegus calpodendron
Infrequent to rare throughout

Conyza canadensis
Common throughout

Cryptotaenia canadensis
Common throughout

Calamagrostis canadensis
Infrequent to rare in westernmost counties; frequent to common elsewhere

Cercis canadensis
Common southeast; infrequent south central and southwest; adventive northeast

Cornus canadensis
Rare northeast: Allamakee County, Clayton County, Delaware County and Winneshiek county

Diarrhena americana
Rare and local throughout

Chenopodium capitatum
Rare northeast and east central: Allamakee County 1939 and Johnson county 1907

Croton capitatus
Infrequent to rare south; loess bluffs in northwest and southwest

Carex careyana
Rare northeast and east central

Carpinus caroliniana
Common northeast; infrequent north central and southeast

Carex cephalantha
Rare north central: Hancock county

Cuscuta cephalanthii
Infrequent to rare throughout, except not reported southwest

Carex cephaloidea
Rare to infrequent e three-quarters

Carex cephalophora
Frequent to common southeast three-quarters

Cardaria chalapensis
Rare southwest: Page county

Vicia americana
Rare northwest and north central: Emmet county 1884 and Hancock county

Crataegus chrysocarpa
Rare north; all records before 1950

Castilleja coccinea
Infrequent to rare north central, and in northwest: Sioux county

Crataegus coccinea
Rare central and east: Dubuque county, Hardin county, Lee county, Linn county and Wapello county

Carex communis
Rare southern half; infrequent in Paleozoic Plateau

Commelina communis
Absent northwest and extreme northeast; infrequent to frequent elsewh

Carex comosa
Frequent in lakes area; rare elsewhere

Carex conjuncta
Rare to infrequent throughout

Ranunculus aquatilis
Rare northeast and east central

Carex convoluta
Common northern half

Carya cordiformis
Infrequent northwest and north central; common elsewhere

Corylus cornuta
Frequent in Paleozoic Plateau; infrequent rest of northeastern quarter

Cuscuta coryli
Infrequent central and north central

Carex crawei
Rare northwest, north central and east central: Emmet county 1904, Floyd county and Johnson county

Carex crawfordii
Rare west central and northwest

Carex crinita
Rare east central and southeast: Jefferson county 1934 and Linn county

Carex cristatella
Rare northwest and east; common southwest; infrequent to frequent elsewh

Rosa arkansana
Rare northwest; infrequent southern half

Crataegus crus-galli
Infrequent southwest and extreme east; frequent remainder of southern half

Carex assiniboinensis
Rare southeast and south central: Henry county, Lee county, Louisa county, Mahaska county and Muscatine county

Cuscuta cuspidata
Infrequent to rare throughout

Centaurea cyanus
Rare escape from cultivation

Aristida basiramea
Rare northern half; frequent southern half

Ceratophyllum demersum
Frequent south and in lakes area; rare to infrequent north

Castanea dentata
Rare: scattered trees persisting from cultivation

Quercus borealis
Frequent southern half; infrequent northwest and northeast; rare north central

Carex deweyana
Infrequent in Paleozoic Plateau; rare in lakes area and c

Carex diandra
Rare central, northwest, north central and east central: Cerro Gordo County 1917, Dickinson county, Emmet county 1925, Johnson county 1941, Webster county 1909 and Winnebago county 1899

Cyperus diandrus
Rare throughout most of state

Centaurea diffusa
Rare northwest: Sioux county

Cirsium discolor
Frequent to common throughout

Crataegus disperma
Rare south central and southeast: Davis County 1940, Decatur County 1940 and Wapello county 1940

Carex douglasii
Rare central: Jasper county 1904

Cardamine douglassii
Rare southeastern quarter

Cardaria draba
Infrequent north central and southwest; rare northwest and south central

Artemisia campestris
Frequent to common throughout most of state; rare in Paleozoic Plateau and extreme north

Carex eburnea
Rare to infrequent northern half and southwest; frequent e

Carex eleocharis
Frequent northwest, especially in lakes area

Crotonopsis elliptica
Rare southwest: Ringgold county

Carex emoryi
Rare southwest, in lakes area and in Paleozoic Plateau

Cyperus engelmannii
Rare northern half

Viola canadensis
Rare southeast: Lee county 1931, Louisa county and Muscatine county

Cyperus erythrorhizos
Frequent south; infrequent to rare northern half and east

Cyperus esculentus
Frequent to common southern half and north central; infrequent to rare elsewhere

Chamaecrista fasciculata
Frequent to common throughout

Cheilanthes feei
Infrequent northeast

Polygonum cespitosum
Rare northwest and southeast: Dickinson county and Louisa county

Cyperus filiculmis
Common locally in extreme northeast; frequent southern half; rare elsewhere

Cirsium flodmanii
Common northwest; frequent west; rare northeast

Carex chordorrhiza
Common throughout most of state; rare northwest

Carex foenea
Rare northwest: Clay County 1936

Cucurbita foetidissima
Rare southern half

Ranunculus circinatus
Rare central, east central and southeast: Des Moines county, Iowa county 1928 and Story county 1907

Cystopteris fragilis
Rare in Paleozoic Plateau, central and northwest

Carex frankii
Rare southeast, south central and extreme e

Chelone glabra
Rare throughout most of state; not reported from extreme w

Galium concinnum
Frequent southeastern quarter; rare northeast: Clayton County

Chenopodium glaucum
Rare west central, north central, east central, southeast, and southwest

Cuscuta glomerata
Common north central; infrequent southeast; infrequent to rare western half

Cerastium glomeratum
Rare northwest and east: Buchanan County, Cedar County, Jones county, Linn county 1896, Lyon county, Muscatine county and Scott county 1895

Carex gracilescens
Rare southeast: Des Moines county and Wapello county 1938

Carex gracillima
Rare north except frequent in Paleozoic Plateau

Polygonum cuspidatum
Rare escape from cultivation

Carex davisii
Rare north central; infrequent eastern half

Carex gravida
Frequent to common throughout

Carex grayi
Infrequent southeastern two-thirds

Cuscuta gronovii
Infrequent to rare eastern two-thirds; rare northwest: Dickinson county, Emmet county and Lyon county

Carex haydenii
Rare to infrequent northern half; rare southern half

Carex heliophila
Infrequent throughout

Botrychium dissection
Common northwest and extreme northeast; frequent southwest; infrequent central

Callitriche heterophylla
Rare: scattered throughout

Cirsium hillii
Not reported west and south; rare to infrequent elsewhere

Carex hirsutella
Frequent southeast; rare south central; not reported elsewh

Carex hirtifolia
Common in Paleozoic Plateau; infrequent to rare northeast three-quarters

Carex hitchcockiana
Frequent in lakes area; rare to infrequent elsewhere

Carex hyalinolepis
Rare southwest: Fremont county

Chenopodium hybridum
Frequent southwest; infrequent northeast; rare northwest: Dickinson county

Quercus ellipsoidalis
Common north central; infrequent to frequent elsewh

Carya illinoensis
Rare southeastern quarter, northeast (Dubuque county); introduced in north central (Kossuth county)

Cuscuta indecora
Rare west and east central: Clinton County, Harrison county, Linn county, Lyon county and Pottawattamie county

Calamagrostis inexpansa
Frequent in lakes area; rare remainder of north

Carex interior
Rare to infrequent eastern two-thirds

Cichorium intybus
Rare northeast; common elsewhere

Callirhoe involucrata
Rare northwest and southern half

Chrysosplenium iowense
Rare northeast and east central: Allamakee County, Clayton County, Dubuque county, Fayette county, Howard county, Jackson county and Winneshiek county

Centaurea jacea
Rare northwest: Cherokee County 1924

Carex jamesii
Rare to infrequent e three-quarters

Carya laciniosa
Rare southeastern quarter

Carex lacustris
Frequent north central; rare northwest and southeast

Cynanchum laeve
Frequent southwest; rare southeast: Lee county and Louisa county in late 1800's

Carex laeviconica
Rare in much of state; not reported from southeast

Carex laevivaginata
Rare to infrequent throughout

Coreopsis lanceolata
Rare southeast

Carex lanuginosa
Common in lakes area; rare extreme east; infrequent to frequent elsewh

Mimulus glabratus
Rare central, northwest, east central and southeast

Chasmanthium latifolium
Rare southeast: Lee county

Carex laxiculmis
Rare southeastern quarter

Carex leavenworthii
Frequent to infrequent southeast; rare northeast

Carex leptalea
Rare northeast and east central: Benton County, Black Hawk County and Buchanan County

Carex limosa
Rare northwest and north central: Emmet county 1892 and Hancock county

Collomia linearis
Rare: adventive in north, east central and south central

Calamovilfa longifolia
Infrequent to rare throughout

Calamovilfa longifolia
Rare southeast: Louisa county and Muscatine county

Cenchrus longispinus
Frequent to common throughout

Ranunculus gmelinii
Rare southeast and south central: Decatur County 1900 and Lee county 1931

Eriophorum gracile
Infrequent to frequent east; rare northwest

Carex lurida
Rare central, southeast and south central: Jefferson county 1945, Lee county 1931, Mahaska county and Story county 1886

Alisma gramineum
Frequent to common throughout

Corallorhiza maculata
Rare northeast: Allamakee County, Clayton County, Dubuque county and Winneshiek county

Cicuta maculata
Frequent to common throughout most of state; rare west

Carex granularis
Infrequent southern half; rare northern half; not reported from Paleozoic Plateau

Centaurea maculosa
Infrequent to rare throughout

Convallaria majalis
Rare escape from cultivation

Chelidonium majus
Rare escape from cultivation: Allamakee County, Black Hawk County, Cherokee County, Iowa county, Johnson county and Winneshiek county

Crataegus margaretta
Infrequent to frequent eastern half

Cassia marilandica
Infrequent southern half; rare northeast and east central

Carex meadii
Rare northwest and northeast; frequent to infrequent elsewhere

Solidago hispida
Rare northeast: Clayton County and Delaware County; disjunorth centralt from north Wise.

Corydalis micrantha
Frequent southeast and south central; infrequent southwest; infrequent to rare north central and northeast

Salsola iberica
Infrequent to rare throughout

Chaenorrhinum minus
Frequent to infrequent southern half; rare northern half

Chenopodium missouriensis
Rare central and southeast: Lee county, Louisa county, Story county and Tama county

Carex molesta
Frequent north, south central and southwest; rare to infrequent elsewhere

Crataegus mollis
Infrequent in Paleozoic Plateau; frequent to common elsewhere

Croton monanthogynus
Rare central, west central and southeast: Davis County, Lee county 1917, Monona county, Van Buren county 1954 and Wapello county 1940

Centaurea moschata
Rare central: Polk county 1928

Cacalia muhlenbergii
Rare northeast (except frequent in Paleozoic Plateau), and in southeast and southwest: Muscatine county and Cass County

Dentaria laciniata
Frequent southeast; rare to infrequent elsewhere

Chenopodium murale
Rare northwest, north central and southeast

Carex muskingumensis
Rare north; infrequent s

Cirsium muticum
Rare northeastern two-thirds

Centaurea nigra
Rare west central: Calhoun County 1911

Stellaria longifolia
Rare west central: Harrison county 1952

Carex normalis
Frequent northeast; infrequent elsewhere

Carduus nutans
Frequent to common western half; rare eastern half

Cerastium nutans
Common southwest; frequent east; infrequent north central and south central

Chelone obliqua
Rare north central, east central and southeast: Clinton County 1930, Des Moines county, Lee county 1898, Mitchell county 1929, Muscatine county 1894 and Scott county

Clematis occidentalis
Rare northeast: Allamakee County, Clayton County, Dubuque county and Winneshiek county

Cephalanthus occidentalis
Common southern half and east; infrequent to rare elsewhere

Celtis occidentalis
Common throughout

Corallorhiza odontorhiza
Rare and local throughout

Asclepias meadii
Frequent to common northwest; infrequent southern half; infrequent to rare northeastern quarter

Cynoglossum officinale
Frequent in Paleozoic Plateau; infrequent to rare elsewhere

Carex oligocarpa
Frequent in Paleozoic Plateau; rare to infrequent elsewhere

Celastrus orbiculatus
Rare escape in northeast and south central: Delaware County and Mahaska county

Conringia orientalis
Infrequent to rare throughout

Carya ovata
Rare northwest; common elsewhere

Coreopsis palmata
Infrequent southeast; frequent to common elsewhere

Caltha palustris
Frequent north central and northeastern quarter; rare northwest, southeast and southwest

Rosa multiflora
Rare in Iowan Surface

Carex peckii
Frequent in Paleozoic Plateau

Helianthus occidentalis
Common in Paleozoic Plateau; rare to infrequent in remainder of northeastern half

Carex pensylvanica
Common throughout

Woodsia oregana
Frequent to infrequent northeastern two-thirds; rare south central: Decatur County

Cuscuta pentagona
Infrequent north central; rare in central, northwest, southeast and south central: Boone County, Dallas County 1919, Lee county 1925, Lyon county 1896 and Mahaska county

Agropyron pectiniforme
Common southeast; frequent south central; infrequent to rare elsewhere

Cacalia plantaginea
Common southwest; infrequent elsewhere

Carex plantaginea
Rare e

Cuscuta polygonorum
Infrequent southeast; rare elsewhere

Chenopodium polyspermum
Rare weed in northwest and east central: Emmet county and Johnson county 1902

Lilium philadelphicum
Infrequent to rare west three-quarters

Carex prairea
Frequent in lakes area; rare e

Chaerophyllum procumbens
Frequent north central and southeast; rare northeast and extreme east

Carex projecta
Rare eastern half and north central

Cystopteris protrusa
Common south; frequent north central; rare northwest and northeast

Crataegus pruinosa
Rare central and southeast: Boone County 1940 and Wapello county 1929

Crataegus punctata
Rare northwest and southeast; frequent to infrequent elsewhere

Cimicifuga racemosa
Rare west central: Woodbury county 1938

Campsis radicans
Infrequent escape from cultivation

Conyza ramosissima
Rare to infrequent throughout

Campanula rapunculoides
Rare escape from cultivation

Cypripedium reginae
Rare and local northeast; formerly scattered eastern two-thirds

Centaurea repens
Rare west central and northwest: Sioux county 1933, Woodbury county

Lotus purshianus
Rare east central: Jones county

Carex retrorsa
Infrequent north central; rare northeast

Sambucus racemosa
Rare central and n

Cyperus rivularis
Frequent to infrequent throughout

Heteranthera reniformis
Frequent to common northwest and south; rare in lakes area

Carex rostrata
Rare in scattered sites throughout

Campanula rotundifolia
Common extreme east and in Paleozoic Plateau; rare central

Chenopodium rubrum
Rare northwest: Clay County 1936, Dickinson county, Emmet county 1922 and Palo Alto county 1935

Cornus rugosa
Common in Paleozoic Plateau; infrequent to rare elsewhere

Crepis runcinata
Rare northwest and northeast: Black Hawk County 1921 and Osceola county 1912

Crotalaria sagittalis
Infrequent to frequent northern half; rare southern half

Carex sartwellii
Infrequent throughout

Camelina sativa
Rare north central, northeast and southwest

Cannabis sativa
Common throughout

Carex saximontana
Rare west central and northwest: Lyon county, Plymouth county and Woodbury county

Centaurea scabiosa
Rare west central and northwest: O'Brien county 1944, Sac county

Celastrus scandens
Infrequent northwest; common elsewhere

Cyperus schweinitzii
Frequent to infrequent northeastern half

Camassia scilloides
Infrequent to rare southern half

Vicia sativa
Common northeastern quarter, except rare in Paleozoic Plateau; infrequent to frequent elsewh

Corydalis sempervirens
Rare northeast: Allamakee County

Calystegia sepium
Common throughout

Cleome serrulata
Rare, persisting only in northwest

Calylophus serrulatus
Common northwest and north central; frequent to infrequent rest of northwestern half

Castilleja sessiliflora
Infrequent northern half and southwest

Carex shortiana
Frequent to infrequent southeast and south central; rare northeast

Centaurea solstitialis
Rare south central and southwest

Paspalum setaceum
Infrequent to frequent throughout

Catalpa speciosa
Infrequent throughout

Calystegia spithamaea
Rare east

Paspalum setaceum
Common in Paleozoic Plateau; rare southeast; frequent to infrequent elsewhere

Carex squarrosa
Rare southeast

Chenopodium standleyanum
Frequent north central, southeast and south central; infrequent northwest and northeast

Cryptogramma stelleri
Rare north central; infrequent northeast

Carex sterilis
Rare northeast: Buchanan County, Chickasaw County, Fayette county and Winneshiek county

Carex sprengelii
Frequent north central and northeast; rare south central and southwest

Cornus stolonifera
Rare in northern tier of counties; absent or rare escape from cultivation elsewh

Carex stricta
Common southwest; rare southeast and extreme east; infrequent to frequent elsewh

Agrostis stolonifera
Common north central

Cyperus strigosus
Frequent to common throughout

Cacalia suaveolens
Rare eastern half and southwest

Carex suberecta
Infrequent north central; rare northeast, southeast and southwest

Chenopodium strictum
Infrequent northwest; rare throughout much of state

Carex sychnocephala
Infrequent northwest, especially in lakes area; rare southeast: Louisa county

Crepis tectorum
Rare escape from cultivation in west central and central

Chorispora tenella
Rare central, west central, northwest and northeast: Clay County, Dubuque county, Plymouth county, Sac county, Story county and Woodbury county 1930

Carex tenera
Not reported east central and southeast; rare elsewhere

Cystopteris tenuis
Frequent northeast; absent west; infrequent elsewhere

Carex tetanica
Rare to infrequent northern half

Croton texensis
Rare southeast: Muscatine county 1897

Caulophyllum thalictroides
Common north central and northeast; infrequent northwest and southeast; rare southwest

Coreopsis tinctoria
Rare escape from cultivation, also adventive from west

Carya tomentosa
Infrequent southeast; rare elsewhere in south

Carex tonsa
Rare east

Callirhoe triangulata
Rare east: Allamakee County, Clinton County and Davis County (early 1900's)

Carex tribuloides
Common southern half; infrequent extreme east; rare northwest

Carex trichocarpa
Rare throughout most of state

Coreopsis tripteris
Infrequent southern half

Calopogon tuberosus
Rare east (all pre-1900 except Linn county 1951)

Carex tuckermanii
Rare central: Jasper county 1897

Carex typhina
Rare southeastern two-thirds

Chimaphila umbellata
Rare northeast and east central: Allamakee County, Fayette county 1895, Jackson county 1896, Linn county 1911 and Winneshiek county

Comandra umbellata
Common throughout

Asclepias tuberosa
Rare northeast: Allamakee County and Dubuque county

Cirsium undulatum
Rare central, northwest, east central, southeast and southwest

Chenopodium urbicum
Rare weed throughout

Coronilla varia
Common, planted along highways throughout

Callitriche verna
Rare in lakes area and in Paleozoic Plateau

Collinsia verna
Rare southeast: Jefferson county 1896 and Washington county

Chloris verticillata
Rare escape from plantings in central and southeast

Carex vesicaria
Infrequent north central and northeast; rare southern half

Clematis virginiana
Frequent to common northern half; infrequent southern half

Claytonia virginica
Frequent to common throughout

Coeloglossum viride
Infrequent northeast three-quarters

Cuphea viscosissima
Rare southeast: Davis County, Jefferson county 1935 and Lee county 1917

Cirsium vulgare
Frequent to common throughout

Cerastium vulgatum
Frequent eastern half; infrequent north central

Carex vulpinoidea
Common throughout

Carex woodii
Infrequent to rare northeast

Cypripedium X andrewsii
Rare northeast and south central: Bremer County, Chickasaw County, Decatur County, Fayette county and Howard county

Cystopteris X laurentiana
Rare northeast: Allamakee County n.d., Howard county and Winneshiek county

Cystopteris X tennesseensis
Rare eastern half

Dichanthelium acuminatum
Rare eastern quater; frequent to common elsewhere

Dichanthelium acuminatum
Rare west; frequent to common elsewhere

Dichanthelium acuminatum
Rare east: Bremer County, Clinton County, Jones county, Louisa county and Scott county

Dichanthelium acuminatum
Infrequent northeastern half

Gentiana puberulenta
Infrequent to rare south three-quarters

Dodecatheon amethystinum
Rare northeast and east central: Allamakee County, Clayton County, Dubuque county, Jackson county and Winneshiek county

Dianthus armeria
Infrequent to rare southern half

Dulichium arundinaceum
Rare north central, northeast, southeast and south central

Dichanthelium boreale
Rare northeast: Black Hawk County, Buchanan County and Clayton County 1923

Desmodium canadense
Common northwest, northeast and south; infrequent to frequent elsewh

Dicentra canadensis
Frequent northeastern quarter; absent west; infrequent elsewhere

Dalea Candida
Common western half; frequent eastern half; absent from Loess Hills

Rubus allegheniensis
Infrequent northwest; rare southwest

Desmodium canescens
Infrequent to rare throughout

Delphinium carolinianum
Rare central, southeast and south central: Lee county, Mahaska county and Poweshiek county

Daucus carota
Frequent to common throughout

Dryopteris carthusiana
Common northeast; infrequent southeast; rare central

Digitaria ciliaris
Rare southwest: Fremont county, Mills county, Page county, Pottawattamie county

Dichanthelium clandestinum
Infrequent to rare southeast

Dryopteris cristata
Rare eastern half

Dicentra cucullaria
Frequent northwest; common elsewhere

Desmodium cuspidatum
Common northeast; infrequent to rare elsewhere

Dichanthelium depauperatum
Rare central, north central and extreme east

Didiplis diandra
Rare eastern half

Dalea enneandra
Common southwest; infrequent northwest

Digitaria filiformis
Rare southeast: Des Moines county, Jefferson county 1935, Lee county 1923 and Muscatine county 1898

Dactylis glomerata
Common escape from cultivation throughout

Desmodium glutinosum
Frequent to common throughout most of state; rare northwest

Dryopteris goldiana
Frequent northeast; rare central and south central

Desmodium illinoense
Frequent to common southern half and east; rare elsewhere

Desmanthus illinoensis
Common southwest in loess; infrequent to rare elsewhere

Dryopteris intermedia
Rare central and northeast: Allamakee County, Clayton County, Dubuque county and Webster county 1903

Digitaria ischaemum
Frequent to common throughout

Cornus foemina
Not reported from northwest; frequent to common elsewhere

Dipsacus laciniatus
Infrequent south; rare northeast and east central: Clinton County, Delaware County, Jackson county and Jones county

Dichanthelium latifolium
Frequent to infrequent eastern two-thirds

Dichanthelium leibergii
Common north central; rare northwest and southeast; infrequent elsewhere

Dalea leporina
Infrequent southern half; rare northwest and east; frequent on Missouri R. floodplain

Dichanthelium linearifolium
Rare west central, southeast and south central: Guthrie county, Marion county and Wapello county

Diervilla lonicera
Common in Paleozoic Plateau; rare rest of northeast and southeast

Dasistoma macrophylla
Infrequent southeast and south central

Dryopteris marginalis
Rare central and northeast: Allamakee County, Dubuque county 1922 and Hardin county

Dodecatheon meadia
Common in Iowan Surface; infrequent southeast; rare in Des Moines lobe and in Paleozoic Plateau

Diplotaxis muralis
Rare central and north

Draba nemorosa
Rare northeast: Dubuque county

Desmodium nudiflorum
Infrequent in Paleozoic Plateau; rare remainder of eastern half

Dichanthelium oligosanthes
Rare throughout

Dichanthelium oligosanthes
Frequent to common throughout

Dichanthelium oligosanthes
Frequent northwest; rare elsewhere

Dirca palustris
Frequent in Paleozoic Plateau, extreme east and central; rare to absent elsewh

Desmodium paniculatum
Common southeast; infrequent to rare south central and southwest; rare northern half

Dyssodia papposa
Infrequent northwest and southern half of state

Dracocephalum parviflorum
Rare north, east central and south central

Dichanthelium perlongum
Rare, eastern two-thirds

Descurainia pinnata
Rare southwest; frequent to common elsewhere

Dalea purpurea
Frequent to common throughout

Draba reptans
Frequent in sandy places throughout

Drosera rotundifolia
Rare north central: Hancock county

Dichanthelium sabulorum
Infrequent to rare eastern half

Dichanthelium sabulorum
Rare northeast: Allamakee County

Digitaria sanguinalis
Common throughout

Desmodium sessilifolium
Rare central, northeast and southeast: Black Hawk County 1895, Des Moines county, Lee county and Poweshiek county

Descurainia sophia
Frequent northwest; rare southwest, and in southeast: Muscatine county 1890

Danthonia spicata
Infrequent to rare throughout

Distichlis spicata
Rare western half, and in central: Tama county

Datura stramonium
Frequent southern half; infrequent to rare northern half

Dipsacus sylvestris
Rare escape from cultivation southern half

Diodia teres
Rare east: Clinton County, Des Moines county, Dubuque county, Jackson county, Lee county, Louisa county and Muscatine county 1924

Delphinium tricorne
Infrequent to rare southern half

Draba verna
Rare northeast: Buchanan County

Decodon verticillatus
Rare northeast and east central: Allamakee County and Scott county 1890

Dalea villosa
Rare northeast: Black Hawk County

Dioscorea villosa
Common northwest; infrequent to rare elsewhere

Delphinium virescens
Infrequent south central; rare southeast; frequent to common elsewhere

Diospyros virginiana
Rare southeast and south central: Lee county, Louisa county, Marion county and Wayne county; possibly only the Lee county population is native

Dryopteris X boottii
Rare northeast: Allamakee County 1980

Dryopteris X uliginosa
Rare east central: Jackson county 1980

Eleocharis acicularis
Frequent to infrequent throughout most of state

Euonymus alatus
Rare central, east central and west central: Linn county, Webster county and Woodbury county

Eclipta alba
Frequent eastern half; rare north central

Erythronium albidum
Frequent throughout

Eupatorium altissimum
Frequent south; rare to infrequent north

Erythronium americanum
Rare northwest, northeast and south central: Allamakee County, Dubuque county, Fayette county, Lucas county, Marion county, O'Brien county 1921 and Winneshiek county

Echinacea angustifolia
Common in Loess Hills of west; rare in west and south

Elaeagnus angustifolia
Infrequent escape from cultivation throughout

Eriophorum angustifolium
Infrequent northern half; rare south

Epilobium angustifolium
Infrequent northeastern quarter; rare north central

Erigeron annuus
Common throughout

Equisetum arvense
Common throughout

Erysimum asperum
Rare central, west central and southeast: Ida county 1925, Tama county 1895 and Van Buren county 1940

Eleocharis atropurpurea
Rare southeast: Jefferson county 1933, Louisa county and Muscatine county

Euonymus atropurpureus
Infrequent west; rare northeast; frequent elsewh

Elymus canadensis
Common throughout

Elodea canadensis
Common in lakes area; infrequent remainder of northern half; rare east

Eragrostis capillaris
Rare in Paleozoic Plateau, north central, southeast and south central

Erysimum cheiranthoides
Frequent to infrequent northern half; infrequent to rare southern half

Erodium cicutarium
Rare central and northwest: Buena Vista County 1920, Cherokee County 1924 and Story county 1914

Eragrostis cilianensis
Common throughout

Epilobium ciliatum
Common southwest; infrequent to rare elsewhere

Epilobium coloratum
Frequent to common throughout; not reported from extreme west

Euphorbia commutata
Rare northeast: Winneshiek county 1933

Eleocharis compressa
Infrequent to rare throughout most of state

Echinodorus cordifolius
Infrequent southwest; rare northwest, northeast and southeast

Euphorbia corollata
Infrequent northwest; common elsewhere

Echinochloa crusgalli
Common throughout

Euphorbia cyathophora
Frequent to infrequent throughout

Euphorbia cyparissias
Frequent to infrequent throughout

Euphorbia dentata
Frequent to common northwest and southern half ; infrequent to rare elsewhere

Eleocharis engelmannii
Common in Paleozoic Plateau; frequent north central and south central; infrequent to rare elsewhere

Eleocharis erythropoda
Frequent to common western half; infrequent to rare eastern half

Euphorbia esula
Frequent northwest; infrequent to rare elsewhere

Euphorbia falcata
Rare in Loess Hills: Monona county

Equisetum fluviatile
Rare northeast half

Eragrostis frankii
Rare west; infrequent elsewhere

Eragrostis frankii
Rare east

Erucastrum gallicum
Rare west central and northeast: Delaware County, Winneshiek county and Woodbury county

Euphorbia geyeri
Infrequent to rare eastern half

Euphorbia glyptosperma
Frequent to common western half; infrequent to rare eastern half

Carex crus-corvi
Rare central, northwest and north central: Cerro Gordo County 1917, Dickinson county, Emmet county 1893, Hancock county and Webster county 1905

Euthamia graminifolia
Rare extreme west; absent northeast; frequent to infrequent elsewhere

Botrychium dissectum
Rare western half; infrequent east

Erechtites hieracifolia
Frequent to common southern half; rare north central

Cornus drummondii
Frequent to common throughout

Eragrostis hypnoides
Frequent to common throughout

Erysimum inconspicuum
Rare western half, and in central, northwest and northeast: Chickasaw County 1926, Emmet county 1926, Webster county 1906

Eleusine indica
Frequent southern half; rare northern half

Elymus interruptus
Rare northwest: Dickinson county, Emmet county 1922

Chenopodium foggii
Infrequent east; common elsewhere

Epilobium leptophyllum
Frequent in lakes area; otherwise rare to infrequent northern half

Echinocystis lobata
Frequent northwest; infrequent to rare elsewhere

Eleocharis macrostachya
Frequent to common north central and south central; infrequent to rare east

Euphorbia maculata
Infrequent west central, northwest and north central; common elsewhere

Eupatorium maculatum
Common in Paleozoic Plateau; frequent in Iowan Surface; infrequent north central and south central

Euphorbia marginata
Common west, especially in Loess Hills; infrequent to rare southeast and south central

Euphorbia missurica
Rare central and west central: Harrison county and Story county 1880's

Echinochloa muricata
Frequent to common throughout

Euphorbia nutans
Infrequent north central; frequent to common elsewhere

Elodea nuttallii
Frequent southeast; infrequent to rare elsewhere

Ellisia nyctelea
Frequent to common throughout

Eleocharis obtusa
Common in Paleozoic Plateau; infrequent to frequent elsewhere

Euphorbia obtusata
Rare southern two-thirds, and in northwest: Lyon county 1897

Eleocharis olivacea
Rare east central: Johnson county

Eleocharis ovata
Rare north central: Hancock county

Echinacea pallida
Common west; infrequent elsewhere

Eleocharis parvula
Rare northwest: Clay County 1936 and Palo Alto county 1940

Eleocharis pauciflora
Rare northwest: Dickinson county and Emmet county

Eragrostis pectinacea
Common throughout

Euphorbia peplus
Rare southeast: Muscatine county 1891

Eupatorium perfoliatum
Infrequent southeast; frequent elsewhere

Erigeron philadelphicus
Common north central; frequent elsewhere

Eragrostis pilosa
Rare southern half

Eragrostis poaeoides
Rare central and southeast

Equisetum pratense
Frequent northeast; rare central and east central

Euphorbia prostrata
Rare west central and southwest: Harrison county, Mills county and Page county

Erigeron pulchellus
Common in Paleozoic Plateau; rare elsewhere

Echinacea purpurea
Rare in southeast and south central

Eupatorium purpureum
Frequent to common throughout

Erysimum repandum
Rare central, northwest and south: Decatur County, Fremont county, Jefferson county 1933, Lee county, Page county and Story county

Eragrostis reptans
Rare central: Hardin county n.d. (ca. 1905)

Elymus riparius
Rare and local central and northeast

Eupatorium rugosum
Common throughout

Carex retroflexa
Rare escape from cultivation

Equisetum scirpoides
Rare northeast and east central: Allamakee County, Clayton County, Delaware County, Dubuque county, Jackson county and Winneshiek county

Eupatorium serotinus
Frequent southeast; rare southwest

Euphorbia serpens
Infrequent to rare western half

Euphorbia serpyllifolia
Infrequent northwest and north central; rare southwest

Brasenia schreberi
Rare northeast and east central: Allamakee County, Clayton County, Fayette county 1926 and Jones county 1948

Eleocharis smallii
Frequent to common north central; infrequent to rare northeast

Euphorbia spathulata
Rare throughout most of state

Eragrostis spectabilis
Rare northwest; infrequent elsewhere

Echinops sphaerocephalus
Rare northwest and northeast: Bremer County and Clay County 1923

Euphorbia stictospora
Rare west central and northwest: Monona county, Plymouth county and Woodbury county

Epilobium strictum
Rare northeast: Black Hawk County, Bremer County, Buchanan County and Chickasaw County

Potamogeton strictifolius
Common throughout

Equisetum sylvaticum
Rare central, northeast and east central

Eleocharis tenuis
Rare throughout most of state

Elatine triandra
Rare northwest: Dickinson county

Eragrostis trichodes
Rare: scattered in southern half

Elaeagnus umbellata
Occasional escape from cultivation

Eriochloa villosa
Rare: becoming established in scattered locations throughout

Fragaria vesca
Frequent to common throughout

Eriophorum virginicum
Rare northeast: Buchanan County

Elymus virginicus
Frequent to common throughout

Echium vulgare
Rare southwest

Echinochloa walteri
Rare southeastern quarter

Elymus wiegandii
Rare throughout

Eleocharis wolfii
Rare northwest, east central and southwest: Cedar County, Emmet county 1886, Johnson county and Union county

Equisetum X ferrissii
Common northwest and north central; infrequent to frequent elsewhere

Equisetum X litorale
Rare north and east: Allamakee County, Clinton County, Des Moines county, Dickinson county, Jackson county and Mitchell county

Elymus X maltei
Rare in scattered locations

Epilobium X wisconsinense
Rare northwest: Lyon county 1910

Eleocharis xyridiformis
Rare southwest: Page county

Eryngium yuccifolium
Infrequent to frequent throughout most of state; rare in western tier of counties

Fraxinus americana
Infrequent north central; absent northwest; frequent to common elsewhere

Festuca arundinacea
Rare: scattered locations in southeastern quarter

Fimbristylis autumnalis
Rare east

Fagopyrum esculentum
Rare escape from cultivation throughout, not persisting

Froelichia floridana
Common southeast; frequent northeast

Froelichia gracilis
Rare central, east and south central

Fraxinus nigra
Absent west; infrequent to rare southeast and south central; frequent to common elsewhere

Festuca obtusa
Frequent to common throughout

Rumex maritimus
Rare southeast; infrequent elsewhere

Fumaria officinalis
Rare south central and southwest: adventive in Wayne county and Page county

Festuca ovina
Rare throughout

Festuca paradoxa
Rare southeastern half

Festuca octoflora
Frequent to common throughout

Fraxinus pennsylvanica
Common southwest; rare elsewhere

Festuca pratensis
Infrequent throughout

Floerkea proserpinacoides
Rare northeast: Dubuque county

Fraxinus quadrangulata
Rare southeast: Des Moines county and Lee county

Filipendula rubra
Rare northeast and southeast: Fayette county and Muscatine county

Festuca rubra
Rare northeast, east central and south central: Allamakee County, Johnson county and Mahaska county 1915

Fuirena simplex
Rare southwest: Fremont county 1946

Falcaria sioides
Rare west central: Guthrie county 1931

Spiranthes vernalis
Rare southeast; frequent to common elsewhere

Fragaria virginiana
Common throughout

Gentiana alba
Infrequent to rare throughout most of state; not reported northwest

Spiraea alba
Infrequent to rare northeast, and in northwest: Dickinson county

Gentiana andrewsii
Frequent in Iowan Surface and central; infrequent to rare east and south central

Galium aparine
Common throughout

Galium asprellum
Rare northeast: Allamakee County, Clayton County, Delaware County, Dubuque county and Winneshiek county

Gaylussacia baccata
Rare northeast, east central and southeast: Allamakee County, Cedar County, Clinton County, Linn county and Muscatine county

Geranium bicknellii
Rare central, northwest and northeast: Emmet county 1922, Fayette county 1893 and Webster county 1905

Gaura biennis
Frequent to common southern half; infrequent to rare northeastern quarter; rare northwest: Emmet county

Galium boreale
Common northeastern quarter; frequent extreme east; infrequent northwest

Glyceria borealis
Infrequent in lakes area; rare north central and east central: Hancock county and Linn county

Geum canadense
Common throughout

Geranium carolinianum
Frequent to rare southwest; infrequent to rare elsewhere

Galium circaezans
Frequent to common throughout

Gaura coccinea
Frequent in Loess Hills

Polygonum amphibium
Common throughout

Gentianopsis crinita
Rare north central, northeast and in lakes area

Gymnocladus dioica
Frequent to infrequent throughout

Gutierrezia dracunculoides
Rare southwest: Ringgold county

Gymnocarpium dryopteris
Rare in Paleozoic Plateau and in central and east central: Hardin county and Johnson county 1892

Thalictrum dasycarpum
Common in lakes area; frequent in remainder of northern half

Glechoma hederacea
Rare northwest; infrequent southwest; frequent to common elsewhere

Galium labradoricum
Rare north central and northeast: Cerro Gordo County, Chickasaw County, Clayton County, Mitchell county, Winnebago county and Winneshiek county

Geum laciniatum
Rare northwest; frequent to infrequent south and east

Glycyrrhiza lepidota
Frequent to common western half; waif along railroads in eastern half

Geranium maculatum
Not reported northwest; common elsewhere

Glycine max
Common, widely cultivation, not persisting

Gratiola neglecta
Frequent south central; infrequent to rare elsewhere

Gnaphalium obtusifolium
Common eastern half and south central; rare north central

Galium obtusum
Frequent to infrequent throughout

Galinsoga parviflora
Rare escape from gardens

Gaura parviflora
Infrequent in Loess Hills of southwest; rare southeast, and in central and east central: Iowa county 1940 and Story county 1892

Gentianopsis procera
Rare north, and in central: Marshall county 1902

Clematis pitcheri
Infrequent to rare throughout most of state; frequent north central

Goodyera pubescens
Rare and local east

Gaillardia pulchella
Rare west central and northwest: Emmet county 1954, Woodbury county

Gnaphalium purpureum
Rare southeast and south central: Decatur County, Lee county 1931 and Warren county

Senecio pseudaureus
Frequent southwest; infrequent southeast; rare north central

Gentianella quinquefolia
Infrequent to rare northeastern half

Gymnocarpium robertianum
Rare northeast: Allamakee County, Clayton County, Dubuque county and Winneshiek county

Muhlenbergia schreberi
Infrequent central and southeast

Galearis spectabilis
Frequent northeast; rare southwest; infrequent elsewhere

Grindelia squarrosa
Frequent to common west, especially in Loess Hills; infrequent to rare elsewhere

Glyceria striata
Frequent to common southern half and in lakes area; infrequent elsewhere

Galeopsis tetrohit
Rare west central, northeast and southwest

Galium tinctorium
Frequent to infrequent eastern half; rare south central

Gleditsia triacanthos
Common throughout most of state; infrequent northwest

Galium trifidum
Rare north central and northeast: Des Moines lobe and Allamakee County, Winneshiek county

Galium triflorum
Frequent northwest; infrequent north central; common elsewhere

Geum triflorum
Infrequent northeast; rare northwest: Dickinson county

Geum vernum
Rare northwest and south: Jefferson county 1928, Mahaska county 1938, Page county, Taylor county and Wapello county 1939

Galium verum
Rare west: Cass County 1925, Dickinson county, and Greene county 1929

Gratiola virginiana
Rare southeast and south central: Decatur County 1900, Lee county and Muscatine county

Gentiana X billingtonii
Rare north central, northeast, east central and south central: Decatur County, Dubuque county and Johnson county

Helenium amarum
Rare east central: Jones county

Cornus alternifolia
Rare southeast

Helianthus annuus
Common western half; frequent eastern half

Hydrophyllum appendiculatum
Frequent in Paleozoic Plateau; infrequent southern half, east central and southeast; rare elsewhere

Hieracium aurantiacum
Rare north central and northeast: Allamakee County, Clayton County 1935 and Mitchell county

Helenium autumnale
Frequent to common throughout

Helianthemum bicknellii
Frequent to common southern half and northeast; infrequent north central and in lakes area

Hypericum boreale
Rare east central: Linn county

Helianthemum canadense
Common northeast; frequent southwest; rare southeast

Hypericum canadense
Rare northeast: Winneshiek county 1933

Hieracium canadense
Rare north, and in east central and southeast: Linn county, Muscatine county and Scott county late 1800's

Hydrastis canadensis
Rare northeast and east central

Hybanthus concolor
Rare central, northeast and east central: Allamakee County, Boone County, Clayton County, Dubuque county, Jones county and Winneshiek county

Hedyotis crassifolia
Infrequent east

Helianthus decapetalus
Infrequent to rare northeastern quarter and southern half

Hackelia deflexa
Frequent east; infrequent to rare north central and northeast

Helianthus divaricatus
Rare extreme east

Hypericum drummondii
Rare southeast: Van Buren county 1933

Heteranthera dubia
Infrequent northwest and east; rare elsewhere

Hemerocallis fulva
Common escape from cultivation throughout

Hypericum gentianoides
Rare east and south central: Buchanan County, Clinton County 1932, Madison county 1917 and Muscatine county pre-1900

Helianthus gigonteus
Rare southeast and south central

Helianthus grosseserratus
Frequent to common throughout

Heliopsis helianthoides
Frequent to common throughout

Hypoxis hirsuta
Infrequent northeast; frequent to common elsewhere

Helianthus hirsutus
Rare north central, southeast and southwest

Hedeoma hispidum
Frequent to common throughout

Carex festucacea
Frequent southwest; infrequent to rare eastern two-thirds

Hordeum jubatum
Common throughout

Hibiscus laevis
Frequent to infrequent east central, southeast and south central; rare north central, southwest and in Paleozoic Plateau

Heracleum lanatum
Frequent north central; infrequent western half; rare east

Holcus lanatus
Rare central, east central and southeast: Linn county 1919, Louisa county 1919 and Story county 1898

Heteranthera limosa
Rare northwest, southeast and southwest: Fremont county 1888, Lyon county and Muscatine county 1894

Hieracium longipilum
Infrequent in Paleozoic Plateau; rare remainder of eastern half

Humulus lupulus
Infrequent to frequent throughout most of state

Hypericum majus
Infrequent to rare throughout most of state

Hesperis matronalis
Infrequent to rare western half and east

Helianthus maximiliani
Common north central; infrequent west

Hemicarpha micrantha
Rare north central and northeast; infrequent southeast

Helianthus mollis
Rare southeast and south central: Decatur County and Muscatine county 1896

Hypericum mutilum
Frequent southeast; infrequent south central; rare northeastern quarter

Hedyotis nigricans
Frequent to common in Loess Hills and southwest

Carex lupuliformis
Common east and north central; frequent south central; rare northwest

Carex lupulina
Rare northeast and southeast: Allamakee County and Henry county 1942

Viola macloskeyi
Common in Paleozoic Plateau; infrequent remainder of east

Hierochloe odorata
Infrequent northern half

Hystrix patula
Rare northwest; common elsewhere

Hypericum perforatum
Frequent southwest; infrequent to rare elsewhere

Helianthus petiolaris
Rare south central and southwest; frequent southeast

Hypericum prolificum
Frequent southeast; rare south central and southwest

Hedeoma pulegioides
Common southeast; infrequent to rare extreme east, south central and southwest

Hypericum punctatum
Frequent to common south and in Iowan Surface; rare north central and in Paleozoic Plateau

Hordeum pusillum
Infrequent to frequent south; rare north

Hypericum pyramidatum
Frequent to infrequent northern half; infrequent to rare southern half

Monarda punctata
Rare south central: Lucas county

Galinsoga quadriradiata
Common northeastern quarter and southwest; infrequent to frequent elsewh

Helianthus rigidus
Common western half; infrequent eastern half

Helianthus rigidus
Common west; infrequent east

Hieracium scabrum
Frequent south and in Paleozoic Plateau; rare to infrequent elsewhere

Heleochloa schoenoides
Rare central: Polk county

Hypericum sphaerocarpum
Frequent to common eastern half; rare northwest and southwest: Fremont county 1890, Palo Alto county 1939

Helianthus strumosus
Rare northwest; frequent elsewhere

Hudsonia tomentosa
Rare east central: Jackson county

Hibiscus trionum
Rare northeast; frequent to common elsewhere

Helianthus tuberosus
Infrequent north; frequent to common south

Hieracium umbellatum
Common in Paleozoic Plateau; infrequent remainder of north; rare southeast

Holosteum umbellatum
Rare west central, northeast and southeast: Des Moines county, Dubuque county and Woodbury county

Heterotheca villosa
Rare northwest and east central: Clinton County, Jackson county and Lyon county

Hackelia virginiana
Common in Paleozoic Plateau and east; infrequent to frequent elsewhere

Hamamelis virginiana
Infrequent extreme east, except common in Paleozoic Plateau

Hydrophyllum virginianum
Common northwestern half; frequent southeastern half

Hordeum vulgare
Infrequent escape from cultivation throughout but not persisting

Hippuris vulgaris
Rare northwest and north central: Cerro Gordo County 1903, Clay County 1936 and Dickinson county 1948

Iva annua
Rare southeast and southwest: Des Moines county, Jefferson county 1935 and Pottawattamie county 1898

Isopyrum biternatum
Frequent to common central and northeast; infrequent to rare elsewhere

Impatiens capensis
Frequent to common throughout

Ipomoea coccinea
Rare escape from cultivation

Ipomoea hederacea
Frequent southwest; infrequent to rare elsewhere

Inula helenium
Rare east: Johnson county, Muscatine county and Winneshiek county

Equisetum hyemale
Rare east central: Clinton County

Impatiens pallida
Infrequent northwest and north central; frequent to common elsewhere

Ipomoea pandurata
Frequent southeast; rare northwest, northeast, east central and south central: Clayton County 1920, Decatur County 1898, Johnson county 1933, Linn county 1902, Lyon county 1896 and Winneshiek county

Iodanthus pinnatifidus
Rare to infrequent southern half and northeast

Ipomoea purpurea
Frequent north central and south central; infrequent to rare elsewhere

Ipomopsis rubra
Rare escape from cultivation in north central, east central and southwest: Cerro Gordo County, Fremont county and Johnson county

Iris shrevei
Frequent to common throughout most of state; especially common in lakes area and north central

Iberis umbellata
Rare escape from cultivation in south central: Madison county 1942

Ilex verticillata
Rare north central, northeast and east central: Allamakee County, Bremer County, Howard county, Linn county and Mitchell county

Iris X germanica
Rare: occasionally persists from cultivation

Iva xanthifolia
Frequent to infrequent western half and north central; rare southeast: Muscatine county 1892

Juncus acuminatus
Infrequent southeast; rare northeast and southwest

Viola pedatifida
Rare west central and northwest: Dickinson county, Harrison county 1909 and Woodbury county 1888

Justicia americana
Rare southeast: Des Moines county, Henry county, Jefferson county 1935 and Lee county 1931

Heuchera richardsonii
Infrequent in lakes area; rare elsewhere

Juncus bufortius
Rare and scattered, north and southeast

Astragalus agrestis
Rare south central and eastern quarter

Juglans cinerea
Common east and north central; infrequent southwest

Polygonum amphibium
Infrequent northeast; rare central: Hardin county

Jeffersonia diphylla
Rare northeast: Allamakee County, Clayton County, Dubuque county and Fayette county

Juncus dudleyi
Frequent to common north central, south central and in lakes area; infrequent elsewhere

Juncus effusus
Rare east

Populus deltoides
Rare northeast and east central

Juniperus horizontalis
Rare north central and northeast: Allamakee County and Floyd county

Juncus interior
Frequent to common southern half; infrequent northern half

Ipomoea lacunosa
Rare southwest and southeast: Des Moines county, Fremont county, Muscatine county 1891 and Page county

Juncus marginatus
Rare east central and southeast: Cedar County, Clinton County, Muscatine county 1892 and Scott county

Juglans nigra
Common throughout

Juncus nodosus
Infrequent to rare throughout

Juncus tenuis
Rare northwest; common elsewhere

Juncus torreyi
Frequent to common western half; infrequent to rare eastern half

Juncus vaseyi
Rare northeast: Black Hawk County and Howard county

Juniperus virginiana
Common eastern half; infrequent to frequent west

Juncus X nodosiformis
Rare northwest: Dickinson county

Krigia biflora
Rare north; frequent east

Krigia dandelion
Rare southwest: Union county

Koeleria macrantha
Infrequent east; frequent to common elsewhere

Kochia scoparia
Common north central and southwest; rare eastern half; infrequent elsewhere

Kummerowia stipulacea
Common southeast; infrequent south central; rare northeast

Kummerowia striata
Rare southeast: Muscatine county

Krigia virginica
Rare east central and southeast: Des Moines county, Clinton County, Jackson county, Louisa county and Muscatine county

Luzula acuminata
Infrequent e

Lythrum alatum
Common in lakes area; infrequent to rare elsewhere

Ludwigia alternifolia
Infrequent southeast and south central

Ribes americanum
Rare in Paleozoic Plateau; infrequent northwest and extreme east; common elsewhere

Lamium amplexicaule
Infrequent south and north central; rare northwest and northeast: Palo Alto county and Winneshiek county

Lindernia anagallidea
Rare western two-thirds

Lithospermum arvense
Rare southeast and south central: Des Moines county 1937, Lee county, Mahaska county 1938 and Muscatine county 1892

Lycopus asper
Infrequent west; rare in lakes area and extreme east

Liatris aspera
Common eastern two-thirds; infrequent elsewhere

Leontodon autumnalis
Rare southwest: Page county

Lactuca biennis
Common in lakes area; rare north central, and in northeast and east central: Jones county and Winneshiek county

Amaranthus powellii
Rare northeast: Clayton County and Winneshiek county

Lepidium campestre
Frequent to infrequent southern half; rare north central and southeast

Linaria canadensis
Infrequent e

Laportea canadensis
Frequent northwest; common elsewhere

Lactuca canadensis
Infrequent northwest; common elsewhere

Lithospermum canescens
Common throughout

Lespedeza capitata
Common throughout

Leonurus cardiaca
Frequent to common throughout

Lobelia cardinalis
Frequent northeast and southeast; infrequent south central; rare north central

Lithospermum caroliniense
Frequent to infrequent northeast; rare to infrequent southern half

Lysimachia ciliata
Infrequent to common throughout

Lycopodium clavatum
Rare northeast and east central: Allamakee County, Iowa county and Johnson county

Lysimachia clethroides
Rare escape from cultivation

Leptoloma cognatum
Frequent to common eastern quater; rare south central

Lotus corniculatus
Infrequent to rare throughout

Lespedeza cuneata
Rare southern half

Liatris cylindracea
Rare northeastern third; frequent in Paleozoic Plateau

Lespedeza daurica
Rare southeast: Louisa county

Lycopodium dendroideum
Rare northeast: Allamakee County, Clayton County and Dubuque county

Lepidium densiflorum
Common northern half; frequent east and south central; rare southeast and southwest

Linnaea borealis
Rare northeast and east central

Verbena bracteata
Common north central, east and in Paleozoic Plateau; frequent southwest; infrequent to rare elsewhere

Lindernia dubia
Common southern half and extreme east; frequent in Paleozoic Plateau; rare elsewhere

Lappula echinata
Common northwest; infrequent to rare elsewhere

Dalea Candida
Not persisting from cultivation

Leptochloa fascicularis
Rare to infrequent northwestern two-thirds of state

Lactuca floridana
Frequent to common southern half; infrequent to rare northern half

Lomatium foeniculaceum
Rare northwest and southwest: Fremont county, Lyon county and Sioux county

Lonicera dioica
Infrequent to rare escape in southern half

Lysimachia hybrida
Rare central and northwest; frequent to common elsewhere

Lithospermum incisum
Common northern half and southwest; rare elsewhere

Lobelia inflata
Frequent to common southeastern two-thirds

Lechea intermedia
Rare west central, east central and northeast: Allamakee County, Benton County, Dubuque county, Guthrie county and Winneshiek county

Lycopodium inundatum
Rare northeast: Buchanan County

Lygodesmia juncea
Common in Loess Hills; frequent to infrequent northwest

Lobelia kalmii
Rare north: Cerro Gordo County, Clayton County 1921, Clay County, Dickinson county, Emmet county, Howard county and Palo Alto county

Lysimachia lanceolata
Frequent to infrequent northern half

Lilium lancifolium
Rare escape from gardens

Lithospermum latifolium
Frequent northeastern quarter; infrequent to rare elsewhere

Leersia lenticularis
Rare eastern half

Lespedeza leptostachya
Rare central, north and south central

Liatris ligulistylis
Rare north central and northeast

Liparis liliifolia
Infrequent east three-quarters

Liparis loeselii
Rare west central, north and east

Lycopodium lucidulum
Rare central, northeast and east central

Lactuca ludoviciana
Infrequent to frequent western half; rare or absent eastern half

Lesquerella ludoviciana
Rare central and northeast: Black Hawk County 1921 and Hardin county 1905

Linaria macedonica
Rare escape from cultivation in south central: Madison county 1942

Lobularia maritima
Rare escape from cultivation in central, north central and east central: Cerro Gordo County, Linn county 1937, Poweshiek county, Tama county 1895

Leonurus marrubiastrum
Frequent in southwest; rare north central, northeast and east central: Cedar County, Johnson county, Winneshiek county and Wright county

Linum medium
Rare southeast: Des Moines county 1925, Jefferson county 1933 and Lee county 1928

Lilium michiganense
Frequent to infrequent throughout

Lemna minor
Common throughout

Lonicera morrowi
Rare escape from cultivation throughout

Leucospora multifida
Rare east: Fayette county 1894, Lee county n.d. (probably 1890's), Louisa county, Muscatine county and Scott county

Luzula multiflora
Rare northeastern half

Lysimachia nummularia
Frequent northeastern quarter; infrequent north central; rare southeast and south central

Lathyrus ochroleucus
Frequent north central; rare northeast and in Paleozoic Plateau

Achillea millefolium
Rare northwest and southwest: Cherokee County, Clay County 1942, Emmet county, Lyon county, O'Brien county, Sioux county and Union county 1926

Leersia oryzoides
Rare northwest; frequent to common elsewhere

Ludwigia palustris
Rare east

Lathyrus palustris
Common north central; infrequent to rare elsewhere

Ludwigia peploides
Rare south: Fremont county, Louisa county and Lucas county

Linum perenne
Rare escape from cultivation

Lolium perenne
Infrequent to rare throughout

Thelypteris palustris
Common southwest; rare north central and east

Lupinus perennis
Rare northeast: Allamakee County and Winneshiek county 1893

Lepidium perfoliatum
Rare central and northwest: Cherokee County 1931 and Story county

Lemna perpusilla
Rare east central: Johnson county 1915

Cardamine parviflora
Infrequent to rare throughout

Carex pedunculata
No records from west central; rare northwest and southwest; infrequent to frequent elsewhere

Cardamine pensylvanica
Rare northeast: Allamakee County, Clayton County and Delaware County 1930

Lonicera prolifera
Common north central and northeast; infrequent to frequent southeast and south central; rare southwest

Liatris punctata
Frequent to common northwest; infrequent rest of western half

Lysimachia punctata
Rare escape from cultivation

Lamium purpureum
Rare central, east central and southeast: Des Moines county, Johnson county and Story county

Aster prenanthoides
Rare northwest, north central and southeast; no records since 1926

Liatris pycnostachya
Rare or infrequent extreme west; frequent to common elsewhere

Lysimachia quadriflora
Common north central; frequent northeastern quarter; infrequent to rare northwest, east central and southeast

Lechea racemulosa
Rare: old central (Webster county) collection, n.d.

Lappula redowskii
Rare throughout

Lespedeza repens
Rare southeast and south central: Henry county 1897, Mahaska county 1921 and Van Buren county 1932

Linum rigidum
Frequent to rare west

Lygodesmia rostrata
Rare west central and northwest: Harrison county and Plymouth county 1927

Lythrum salicaria
Rare throughout, escaping from cultivation and spreading rapidly

Lactuca saligna
Rare southwest: Page county

Lonicera sempervirens
Rare escape in northeast and south central: Delaware County 1891, Mahaska county late 1800's

Lactuca serriola
Common southwestern two-thirds; infrequent to rare elsewhere

Leonurus sibiricus
Rare central: Poweshiek county

Lobelia siphilitica
Infrequent northwest; frequent to common elsewhere

Lobelia spicata
Common north and eastast; frequent to infrequent elsewhere

Liatris squarrosa
Infrequent western half; rare southeast

Lechea stricta
Frequent to infrequent northeast; rare elsewhere

Linum sulcatum
Common southwest; rare southeast; frequent to infrequent elsewhere

Lactuca tatarica
Common west; frequent to infrequent north central and south central

Lonicera tatarica
Frequent escape from cultivation

Lolium temulentum
Rare north central and northeast, not collected since 1922

Lechea tenuifolia
Infrequent south central and southeast; rare north central and northeast

Lysimachia terrestris
Not reported from northwest; infrequent to rare elsewhere

Lysimachia thyrsiflora
Infrequent north central and in lakes area; rare northeast and southeast

Lemna trisulca
Common in lakes area; infrequent to rare elsewhere

Lathyrus tuberosus
Rare southeast, and in southwest: Cass County and Adams County 1947

Liriodendron tulipifera
Commonly planted in southeast; a population is reproducing in Lee county

Lycopus uniflorus
Frequent northern half; rare elsewhere

Linum usitatissimum
Rare escape from cultivation, not persisting

Carex umbellata
Common northwest and north central; infrequent to absent elsewhere

Lechea villosa
Rare east: Jefferson county 1946, Jones county, Lee county 1923 and Winneshiek county 1932

Lespedeza violacea
Common southeast; infrequent central and south central; rare northeast and southwest

Lespedeza virginica
Frequent southeast; rare south central and southwest

Leersia virginica
Common in Paleozoic Plateau; infrequent to frequent elsewhere

Lepidium virginicum
Rare northwest; frequent to common elsewhere

Lycopus virginicus
Not reported northwest; infrequent to rare elsewhere

Leucanthemum vulgare
Frequent to common southwest, south central and in Paleozoic Plateau; infrequent to rare remainder of northeast and southeast

Linaria vulgaris
Frequent southeast and southwest; infrequent elsewhere

Lycopodium X bartleyi
Rare northeast: Allamakee County and Clayton County

Mimulus alatus
Rare southeast and south central

Morus alba
Common throughout

Melilotus alba
Common throughout

Mirabilis albida
Rare northwest, north central and south central

Myosoton aquaticum
Rare north central, northeast and east central

Mentha arvensis
Rare northwest; infrequent in Iowan Surface; frequent to common elsewhere

Muhlenbergia asperifolia
Rare central, west central and northwest: Boone County, Clay County 1948, Dickinson county, Monona county, Story county 1923 and Woodbury county

Megalodonta beckii
Rare northwest and north central: Cerro Gordo County 1901 and Dickinson county

Muhlenbergia bushii
Rare southwest and southeastern quarter

Maianthemum canadense
Common in Paleozoic Plateau, rare in remainder of east

Menispermum canadense
Frequent to common throughout

Montia chamissoi
Rare northeast: Fayette county 1898

Matricaria chamomilla
Rare east central and southeast: Johnson county 1927 and Muscatine county 1895, Scott county

Muhlenbergia cuspidata
Common in lakes area and in Loess Hills; rare central and northeast

Mentzelia decapetala
Rare west central and northwest: Harrison county, Plymouth county and Woodbury county

Monarda didyma
Rare east: Allamakee County 1922, Lee county 1924 and Scott county 1880's

Mitella diphylla
Frequent to common northeastern quarter; infrequent north central; rare southeast and south central

Milium effusum
Rare northeast: Allamakee County

Myriophyllum exalbescens
Infrequent north central, in Iowan Surface and in lakes area; rare south central and southwest

Monarda fistulosa
Common throughout

Medicago folcata
Rare central and west: Lyon county, Marshall county, Page county, Sac county and Sioux county

Muhlenbergia frondosa
Infrequent to rare west; frequent to common elsewhere

Juniperus communis
Rare north, east and southwest

Muhlenbergia glomerata
Rare north central and east

Myriophyllum heterophylum
Rare central, northwest and north central: Clay County 1895, Dickinson county 1901, Emmet county, Palo Alto county 1938, Webster county 1905 and Winnebago county

Mirabilis hirsuta
Frequent to infrequent western half

Malvastrum hispidum
Rare east central and southeast: Muscatine county 1895 and Scott county 1898

Monotropa hypopithys
Rare northeast, southeast and south central: Allamakee County, Appanoose County, Clayton County 1921, Dubuque county, Lee county and Winneshiek county 1903

Malus ioensis
Frequent to common throughout

Moehringia lateriflora
Frequent in Paleozoic Plateau and in Iowan Surface; infrequent southeast

Medicago lupulina
Frequent to common throughout

Matricaria maritima
Rare southeast: Muscatine county 1925

Matricaria matricarioides
Frequent to common northeastern two-thirds; infrequent w

Muhlenbergia mexicana
Common north central; infrequent to rare elsewhere

Minuartia michauxii
Rare northeast and east central: Allamakee County, Clinton County, Delaware County, Dubuque county, Jackson county, Jones county and Winneshiek county 1899

Myosotis micrantha
Rare northeast: Dubuque county

Myosurus minimus
Infrequent east central and south

Melica mutica
Rare southwest: Union county 1898

Malva neglecta
Common southwestern half; infrequent to rare elsewhere

Melica nitens
Rare central and east

Mitella nuda
Rare northeast: Allamakee County

Monolepis nuttalliana
Rare southwest and central: Page county and Story county 1917

Mirabilis nyctaginea
Common throughout

Melilotus officinalis
Common throughout

Mertensia paniculata
Rare northeast: Allamakee County, Clayton County, Fayette county, Howard county and Winneshiek county

Malva parviflora
Rare northwest: Emmet county

Myriophyllum pinnatum
Rare northeast and south: Decatur County 1899, Dubuque county 1900, Fremont county, Lee county, Lucas county, Muscatine county and Ringgold county 1898

Maclura pomifera
Common escape from cultivation, especially in southern half

Platanthera praeclara
Frequent to common east and in Paleozoic Plateau; rare south central, southwest and in Iowan Surface

Marsilea quadrifolia
Rare southeast and south central: Decatur County and Van Buren county

Muhlenbergia racemosa
Frequent to common throughout

Mitchella repens
Rare northeast: Dubuque county 1901 and Winneshiek county

Mimulus ringens
Infrequent northwest; common elsewhere

Malva rotundifolia
Frequent to common throughout

Morus rubra
Infrequent to frequent southwestern half

Miscanthus sacchariflorus
Infrequent escape throughout, but increasing in abundance

Medicago sativa
Common escape from cultivation

Madia sativa
Rare waif from western plains in northwest and south central: Emmet county and Mahaska county 1930's

Ammannia robusta
Frequent southeastern two-thirds

Muhlenbergia sobolifera
Infrequent to rare southeastern two-thirds

Mentha spicata
Frequent cultivation, occasionally escaping or persisting

Myriophyllum spicatum
Rare: Hancock county

Machaeranthera spinulosa
Common southwest; frequent west central and northwest

Matteuccia struthiopteris
Infrequent to frequent east; rare elsewhere

Muhlenbergia sylvatica
Rare east

Malus sylvestris
Rarely escaping from cultivation

Malva sylvestris
Rare escape from cultivation, no records since 1924

Muhlenbergia tenuiflora
Rare east and south central

Menyanthes trifoliata
Rare northern half, and in southeast: Muscatine county

Monotropa uniflora
Infrequent to rare throughout most of state

Malaxis unifolia
Rare central and east: Iowa county 1923, Johnson county 1907, Muscatine county 1893, Story county 1897, Tama county n.d. (pre-1900) and Winneshiek county 1879

Myosotis verna
Infrequent to rare southeastern two-thirds

Malva verticillata
Rare escape from cultivation, last record in 1929

Mollugo verticillata
Frequent to common throughout

Myriophyllum verticillatum
Rare central, northwest and northeast: Black Hawk County, Dickinson county, Emmet county, Palo Alto county 1938 and Webster county 1906

Scleria verticillata
Rare northwest: Lyon county

Mertensia virginica
Frequent to infrequent eastern half; rare western half

Melanthium virginicum
Infrequent central, southeast and south central; rare northeast

Marrubium vulgare
Infrequent south and east central

Mentha X gentilis
Frequent cultivation, occasionally escaping or persisting

Mentha X piperita
Frequent cultivation, occasionally escaping or persisting

Nepeta cataria
Frequent to common throughout

Nothocalais cuspidata
Frequent northwest and north central; infrequent west central and southwest

Napaea dioica
Rare north central and northeast: Allamakee County, Black Hawk County, Butler County, Fayette county, Floyd county n.d., Howard county and Winneshiek county

Najas flexilis
Frequent southeast and in lakes area of northwest; rare elsewhere

Najas guadalupensis
Frequent to infrequent in lakes area of northwest, and also north central, southeast and south central; rare elsewhere

Navarretia intertexta
Rare northwest, and in southwest: Page county 1920

Nelumbo lutea
Frequent to rare in Mississippi R. basin; rare along Missouri R.; introduced into a few interior lakes

Nuphar luteum
Not reported from southwest; infrequent to rare elsewhere

Isoetes melanopoda
Common northeast; widely distributed

Neslia paniculata
Rare central, east central and southwest: Johnson county 1908, Linn county 1949, Mills county 1925 and Webster county 1906

Nicandra physalodes
Rare central, northeast and southeast: Allamakee County, Keokuk county, Muscatine county and Story county

Nymphaea tuberosa
Frequent in lakes area; infrequent to rare elsewhere

Onopordum acanthium
Rare central and northeast: Fayette county 1929, Hardin county 1939

Oryzopsis asperifolia
Rare northeast: Allamakee County, Clayton County, Delaware County, Dubuque county and Winneshiek county

Prunus mexicana
Infrequent to rare eastern half

Osmunda cinnamomea
Rare east: Clayton County 1945, Delaware County, Henry county 1938, Jackson county 1905 and Muscatine county

Osmunda claytoniana
Frequent east; infrequent central

Osmorhiza claytonii
Common eastern half; infrequent western half

Oxalis dillenii
Infrequent to rare east and south central

Orobanche fasciculata
Rare northwest and northeast: Allamakee County and Dickinson county 1933

Opuntia fragilis
Rare central, northwest and northeast: Buchanan County, Hardin county and Lyon county

Opuntia humifusa
Rare east and south

Oenothera laciniata
Frequent to infrequent southeastern third; rare northwest, south central and southwest

Oxytropis lambertii
Infrequent west except common in Loess Hills

Osmorhiza longistylis
Infrequent southwest; frequent to common elsewhere

Orobanche ludoviciana
Rare northwest: Lyon county 1896

Opuntia macrorhiza
Rare southwest, west central, central, and northeast: Allamakee County, Guthrie county Montgomery county, Page county and Polk county

Bromus japonicus
Rare northeast and southeast

Humulus japonicus
Frequent to common west; rare east

Orbexilum onobrychis
Rare southeast: Des Moines county and Lee county 1931

Oenothera parviflora
Rare central, north central, northeast and southeast

Oenothera perennis
Rare northeast and east central: Delaware County, Fayette county, Howard county, Linn county and Winneshiek county

Oenothera pilosella
Infrequent southeastern half

Oryzopsis pungens
Rare northeast: Allamakee County and Clayton County

Ophioglossum pusilium
Rare central, northeast and east central

Oryzopsis racemosa
Common in Paleozoic Plateau and extreme east; rare elsewhere in northeastern two-thirds

Betula pumila
Rare east: Allamakee County, Cedar County, Clinton County, Delaware County, Jones county and Muscatine county

Oenothera rhombipetala
Frequent east; infrequent to rare central and south central

Oxypolis rigidior
Rare west, northwest and south; infrequent elsewhere

Onoclea sensibilis
Frequent to common east; infrequent west

Oenothera speciosa
Rare north central and south: Clarke County, Fremont county, Kossuth county and Van Buren county

Oxalis stricta
Frequent southern half; infrequent extreme east and northwest; common northeast

Ornithogalum umbellatum
Rare escape from cultivation

Orobanche uniflora
Rare southeastern third, and in west central: Guthrie county

Oenothera villosa
Common throughout

Oxalis violacea
Infrequent southwestern quarter; frequent to common elsewhere

Ostrya virginiana
Frequent to common throughout

Polygonum achoreum
Frequent to common throughout

Polystichum acrostichoides
Frequent southeast; rare northeast

Prenanthes alba
Frequent to common throughout most of state; not reported from northwest

Populus alba
Infrequent escape from cultivation throughout

Penstemon albidus
Rare northwest: Lyon county, Plymouth county and Sioux county

Phytolacca americana
Frequent southeast; infrequent south central; rare north central, northeast and southwest

Prunus americana
Common throughout

Sisyrinchium angustifolium
Common north central, south central and southwest; infrequent northwest and east central; rare in Paleozoic Plateau

Lycopersicon esculentum
Common north central, south central, and in lakes area

Potamogeton amplifolius
Rare central, northwest, north central and southeast: Cerro Gordo County 1896, Dickinson county, Floyd county 1880's, Hancock county, Muscatine county 1894 and Tama county 1891

Poa annua
Frequent to common throughout, though rarely collected

Potentilla anserina
Rare central, northwest and north central: Dickinson county, Emmet county, Hamilton county 1886, Hardin county ca. 1900 and Wright county 1904

Pteridium aquilinum
Common northeast to rare central and southeast

Potentilla argentea
Rare central and east, and in northwest: Dickinson county and Emmet county 1930

Pediomelum argophyllum
Frequent to common western half; rare northeast

Potentilla arguta
Rare northeast; frequent to infrequent elsewhere

Poa arida
Rare northwest: Lyon county

Plantago aristata
Common southern half; infrequent elsewhere

Polygonella articulata
Rare central and east: Allamakee County, Buchanan County, Clinton County, Hardin county 1902, Jackson county, Louisa county 1910, Muscatine county and Winneshiek county

Phalaris arundinacea
Common throughout

Pyrola asarifolia
Rare northeast: Allamakee County and Winneshiek county

Prenanthes aspera
Frequent to infrequent west; rare elsewhere

Pellaea atropurpurea
Rare northeast and southeast: Allamakee County and Van Buren county

Phragmites australis
Common central and north central; infrequent to rare elsewhere

Polygonum aviculare
Frequent to common throughout

Petunia axillaris
Rare escape from cultivation

Populus balsamifera
Rare escape from cultivation north

Psoralidium batesii
Rare to infrequent southern half and north central

Prunus besseyi
Rare northwest: Lyon county

Phlox bifida
Rare eastern half

Polygonatum biflorum
Common throughout

Poa bulbosa
Rare central, northwest and southeast: Plymouth county, Muscatine county 1922 and Story county 1929

Paronychia canadensis
Rare to infrequent north and southwest; frequent southeast

Polymnia canadensis
Frequent extreme east; infrequent to rare remainder of eastern half

Pedicularis canadensis
Infrequent to rare west; frequent to common elsewhere

Phalaris canariensis
Rare waif throughout, from birdseed

Panicum capillare
Common throughout

Pyrrhopappus carolinianus
Rare east central, southeast and southwest: Jefferson county 1934, Page county and Scott county

Heuchera americana
Rare southwest: Mills county

Poa chapmaniana
Rare east central and southeast: Johnson county 1889, Louisa county n.d. (pre-1900) and Wapello county 1899

Prionopsis ciliata
Rare central and southeast: HAR and Muscatine county

Platanthera clavellata
Rare east: Fayette county 1894, Linn county, and Muscatine county 1894

Penstemon cobaea
Rare southwest: Fremont county

Pyrus communis
Rare central, east central and southeast: Clinton County 1921, Dallas County, Des Moines county, Johnson County and Lee county

Poa compressa
Common throughout

Polygonum convolvulus
Frequent to common throughout

Amaranthus arenicola
Rare east central: Scott county (an 1847 collection by Parry from northeastar Davenport)

Pontederia cordata
Infrequent to rare throughout

Potamogeton crispus
Rare and local, though spreading

Polygala cruciata
Rare northeast and southeast: Buchanan County and Muscatine county 1898

Carex backii
Infrequent east; rare elsewhere

Populus deltoides
Infrequent west

Oenothera biennis
Common throughout

Panicum dichotomiflorum
Infrequent west and northeast; frequent to common elsewhere

Penstemon digitalis
Frequent southeast; rare northeast, east central, south central and southwest

Puccinellia distans
Rare central: Hamilton county

Phlox divaricata
Infrequent northwest; frequent to common elsewhere

Potamogeton diversifolius
Rare northeast, southeast and south central

Polanisia dodecandra
Frequent to common north central, southeast and south central; infrequent elsewhere

Polanisia dodecandra
Common north central; frequent to infrequent elsewhere

Polygonum douglasii
Rare northeast: Allamakee County

Picris echiodes
Rare south central: Clarke County 1924

Pyrola elliptica
Common in northeastern quarter; infrequent east; formerly found in north central and southeast

Potamogeton epihydrus
Rare north central, northeast and southeast: Bremer County, Fayette county 1894, Muscatine county 1896 and Winnebago county 1896

Polygonum erectum
Infrequent to rare east

Pediomelum esculentum
Frequent to common west, especially in Loess Hills; infrequent to rare north central and south central

Paronychia fastigiata
Infrequent southeast and south central

Platanthera flava
Rare north central and east

Potamogeton foliosus
Frequent to common throughout

Pilea fontana
Rare in lakes area and east

Potamogeton friesii
Rare northwest, north central and south central

Perilla frutescens
Rare central, east central and southeast: Clinton County, Davis County 1940, Johnson county, Jones county 1948 and Story county

Potentilla fruticosa
Rare northeast and east central: Allamakee County, Jackson county, Jones county and Winneshiek county

Panicum gattingeri
Rare northwest and southeast: Clay County, Dickinson county and Louisa county

Stipa comata
Rare central; common northeast

Parnassia glauca
Rare northeastern half

Penstemon gracilis
Rare west central and northwest: Harrison county and Lyon county

Potamogeton gramineus
Infrequent north central and in lakes area

Populus grandidentata
Frequent to common north central, northeast and east central; rare southeast

Portulaca grandiflora
Widely cultivation, rarely escapes, not persisting

Penstemon grandiflorus
Frequent to common in Loess Hills and sandy areas of central and east

Physalis heterophylla
Frequent to common throughout

Panicum hillmanii
Rare northwest: Pocahontas county

Platanthera hookeri
Rare and local northeast

Prunus hortulana
Rare southeast: Lee county and Van Buren county

Polygonum hydropiper
Not reported from extreme northwest counties; frequent to common elsewhere

Polygonum hydropiperoides
Rare central, east central, southeast and south central

Platanthera hyperborea
Rare central, northwest and northeast: Cherokee County, Clay County, Dickinson county, Emmet county, Howard county, Story county 1890 and Winneshiek county n.d. (pre-1900)

Potamogeton illinoensis
Frequent north central and in lakes area; rare southeast and southwest

Polygala incarnata
Rare east and southwest

Plantago indica
Rare southeast: Jefferson county 1933

Parthenium integrifolium
Infrequent to rare eastern half

Potentilla intermedia
Rare northeast: Black Hawk County

Salix exigua
Rare escape from cultivation

Polanisia jamesii
Rare east central and southeast: Cedar County, Jackson county and Muscatine county

Platanthera lacera
Rare southeast: Des Moines county and Lee county 1929

Phyla lanceolata
Infrequent northwest and in Iowan Surface; frequent to common elsewhere

Plantago lanceolata
Rare northeast; infrequent extreme east; frequent to common elsewhere; spreading rapidly

Pedicularis lanceolata
Frequent to common northeastern quarter; rare northwest and southern half

Psoralidium lanceolatum
Rare west: Harrison county, Monona county, Pottawattamie county, Sioux county and Woodbury county

Pellaea glabella
Rare central and east: Allamakee County, Scott county n.d. (pre-1900), Story county 1897 and Muscatine county

Polygonum lapathifolium
Common western half and in Paleozoic Plateau; frequent elsewhere

Phryma leptostachya
Frequent to common throughout

Platanthera leucophaea
Rare east: Black Hawk County 1894, Clayton County, Delaware County, Henry county 1843, Iowa county 1903, Johnson county, Linn county 1921 and Muscatine county 1908

Proboscidea louisianica
Rare northwest, east central, southeast and south central: Dickinson county 1912, Emmet county 1883, Keokuk county 1897, Madison county 1910, Muscatine county 1884 and Scott county

Phlox maculata
Frequent northeast; infrequent north central; rare east central, and in south central: Warren county

Plantago major
Common west; infrequent to rare elsewhere

Carex hystericina
Infrequent throughout

Panicum miliaceum
Rare to infrequent southwestern two-thirds

Primula mistassinica
Rare central: Hardin county 1921

Potamogeton natans
Infrequent north central and in lakes area; rare northeast and southeast

Poa nemoralis
Rare central and east central: Boone County, Scott county, Story county

Prunus nigra
Rare central, northwest and northeast: Allamakee County, Boone County 1936, Clay County 1934, Clayton County and Winneshiek county

Carex lasiocarpa
Occasionally persists from cultivation

Potamogeton nodosus
Common in lakes area and north central; infrequent elsewhere

Potentilla norvegica
Common throughout

Polytaenia nuttallii
Infrequent northeast and south central; rare elsewhere

Platanus occidentalis
Frequent to common southern half and east; rare in Paleozoic Plateau

Portulaca oleracea
Common throughout

Physocarpus opulifolius
Frequent to infrequent east and south central; rare north central

Polygonum orientale
Infrequent south and east

Penstemon pallidus
Frequent southeast; rare extreme east and south central

Onosmodium molle
Rare northeast: Allamakee County, Dubuque county and Winneshiek county

Potentilla palustris
Rare in north part of Des Moines lobe, and in north central, northeast and east central: Black Hawk County, Bremer County, Buchanan County, Cerro Gordo County and Jones county

Poa palustris
Common in lakes area and in Paleozoic Plateau; infrequent to rare elsewhere

Proserpinaca palustris
Rare east central and southeast: Clinton County and Muscatine county

Phlox paniculata
Infrequent to rare escape from cultivation throughout

Potentilla paradoxa
Frequent in north part of Des Moines lobe; infrequent northwest; rare southwest

Populus nigra
Frequent to common northeastern half; infrequent southeast and southwest

Plantago patagonica
Common west; infrequent elsewhere

Pulsatilla patens
Common northwest; infrequent in Iowan Surface; rare in Paleozoic Plateau

Potamogeton pectinatus
Common in lakes area; infrequent elsewhere

Podophyllum peltatum
Common eastern two-thirds

Potentilla pensylvanica
Rare northwest: Lyon county and O'Brien county

Cyperus odoratus
Common in Paleozoic Plateau; frequent north central; rare in Iowan Surface and south central

Lomatium orientale
Infrequent northeast; frequent to common elsewhere

Poa paludigena
Common throughout

Prunus persica
Rare escape from cultivation

Polygonum persicaria
Infrequent to rare northeastern quarter; frequent to common elsewhere

Pennisetum petiolare
Rare central: Story county

Physostegia parviflora
Rare west, north central and south central: Clay County, Dickinson county 1948, Greene county, Hancock county, Monroe county and Montgomery county

Phlox pilosa
Infrequent southeast; frequent to common elsewhere

Pycnanthemum pilosum
Frequent southeast; rare northwest: Emmet county 1923

Fraxinus pennsylvanica
Rare east: Allamakee County, Buchanan County, Clinton County, Jackson county, Linn county and Wapello county 1941

Lolium perenne
Rare in scattered locations throughout

Potamogeton praelongus
Rare northwest and north central: Cerro Gordo County 1896, Dickinson county and Emmet county 1895

Phleum pratense
Common throughout

Poa pratensis
Common throughout

Platanthera psycodes
Rare and local northeast and southeast

Polygonatum pubescens
Rare northeast: Allamakee County and Winneshiek county

Physalis pubescens
Rare throughout

Ludwigia polycarpa
Rare escape from cultivation

Philadelphus pubescens
Rare northeast: Dubuque county

Pilea pumila
Rare northwest; frequent to common elsewhere

Prunus pumila
Rare north and southeast: Allamakee County, Buchanan County, Cerro Gordo County 1946, Delaware County, Dickinson county 1928, Louisa county, Lyon county, Muscatine county and Winneshiek county

Polygonum punctatum
Rare northwest; frequent to common elsewhere

Potamogeton pusillus
Frequent in lakes area and southeast; infrequent to rare south central and southwest

Potamogeton pusillus
Rare in lakes area, and in west central: Greene county

Parthenocissus quinquefolia
Frequent northwest; rare north central; common elsewhere

Panax quinquefolius
Frequent northeast and east central; infrequent southeast; rare western half

Prenanthes racemosa
Frequent to common north central and in lakes area; infrequent to rare elsewhere

Polygonum ramosissimum
Common southwest; frequent north central; infrequent eastern half

Potentilla recta
Frequent to infrequent throughout most of state

Polemonium reptans
Common eastern half; infrequent to rare western half

Potamogeton richardsonii
Common in lakes area; rare remainder of northwest and in Paleozoic Plateau

Potentilla rivalis
Rare north and east

Plantago rugelii
Common throughout

Polygonum sagittatum
Frequent northeastern quarter; infrequent southeast and south central

Polygala sanguinea
Frequent to infrequent eastern two-thirds

Pastinaca sativa
Common throughout

Polygonum scandens
Common north central and southwest; frequent eastern half; rare northwest

Pyrola secunda
Rare northwest and northeast: Allamakee County, Delaware County, Emmet county 1928, Winneshiek county

Penthorum sedoides
Infrequent northwest; common elsewhere

Polygala senega
Frequent in Iowan Surface; infrequent in Paleozoic Plateau; rare central and southeast

Prunus serotina
Frequent to common throughout

Carex scoparia
Rare northern half; infrequent southern half

Glyceria septentrionalis
Infrequent to rare southern half

Eupatorium sessilifolium
Infrequent to rare southeastern half

Potentilla simplex
Common eastern half; infrequent to rare western half

Potamogeton spirillus
Rare north central and southeast: Hancock county 1896, Muscatine county 1896 and Winnebago county 1896

Carex stipata
Rare north central and in lakes area, last collected in 1917

Pinus strobus
Rare eastern half; frequent in Paleozoic Plateau

Phlox subulata
Rare escape from cultivation

Poa sylvestris
Rare southeastern half of state

Polygonum tenue
Frequent in Paleozoic Plateau; infrequent to rare elsewhere

Pycnanthemum tenuifolium
Frequent to common southern half; infrequent to rare northern half

Populus tremuloides
Frequent to common northern half; infrequent to frequent southern half

Potentilla tridentata
Rare northeast: Allamakee County and Winneshiek county

Ptelea trifoliata
Frequent southeast and extreme east; rare north central

Poa trivialis
Rare central and northeast: Allamakee County, Clayton County and Story county

Penstemon tubiflorus
Rare central, east central, southeast and south central: Clarke County, Iowa county, Jefferson county 1932, Linn county and Story county

Potamogeton vaseyi
Rare north central, east central and south: Linn county, Louisa county, Lucas county, Ringgold county and Worth county

Polygala verticillata
Frequent southwest; rare north central; infrequent elsewhere

Panicum virgatum
Common throughout

Physostegia virginiana
Rare northwest; infrequent elsewhere

Prunus virginiana
Common throughout

Marsilea vestita
Frequent to common throughout

Pycnanthemum virginianum
Common eastern two-thirds; infrequent to rare west

Polypodium virginianum
Absent southwest and south; rare to infrequent elsewhere

Polygonum virginianum
Common north central and east central; infrequent northwest; frequent elsewh

Plantago virginica
Frequent southeast; infrequent south central; rare southwest

Peltandra virginico
Rare west central, east central and southeast: Cedar County, Des Moines county and Greene county

Parthenocissus vitacea
Frequent to common throughout most of state

Prunella vulgaris
Rare west; occasional elsewhere

Prunella vulgaris
Rare northwest; common elsewhere

Poa wolfii
Rare: scattered locations in eastern half

Populus X rouleauiana
Infrequent to rare eastern half

Potamogeton zosteriformis
Frequent north central and in lakes area; rare northeast, and in east central, southeast and southwest: Fremont county 1905, Linn county 1895, Louisa county and Muscatine county 1895

Quercus alba
Rare southwest; absent northwest; common elsewhere

Quercus bicolor
Infrequent to frequent eastern two-thirds

Rumex occidentalis
Rare northwest; frequent to common elsewhere

Juncus canadensis
Frequent to common northeast; infrequent extreme e

Quercus imbricaria
Common in extreme southeast; infrequent in southern tier of counties

Quercus macrocarpa
Frequent to common throughout

Quercus marilandica
Rare southeast

Quercus muhlenbergii
Common east and southwest; frequent southeast and south central; rare central

Quercus palustris
Common southeast; infrequent east; rare south central and southwest

Quercus prinoides
Rare south central and southwest

Quercus stellata
Rare southeast and south central: Appanoose County, Decatur County, Henry county 1941, Lee county and Van Buren county 1941

Quercus velutina
Common southeastern two-thirds; frequent central; rare northwest

Quercus X bebbiana
Rare southeast: Muscatine county 1895

Quercus X bushii
Frequent southeast and south central

Quercus X deamii
Rare southeast: Des Moines county 1929

Quercus X exacta
Rare southeast: Des Moines county

Quercus X fernowii
Rare southeast: Lee county

Quercus X hawkinsii
Rare south central: Appanoose County 1906

Quercus X leana
Rare southeast: Des Moines county and Keokuk county

Quercus X paleolithicola
Rare southeast: Keokuk county

Quercus X schuettei
Rare northeast: Bremer County

Ranunculus abortivus
Common throughout

Rumex acetosella
Infrequent south central; frequent to common elsewhere

Rosa acicularis
Rare northeast: Allamakee County, Clayton County, Delaware County and Winneshiek county

Ranunculus acris
Rare throughout

Botrychium simplex
Common throughout

Rhamnus alnifolia
Rare in Paleozoic Plateau

Rumex altissimus
Infrequent in Paleozoic Plateau; frequent to common elsewhere

Acer nigrum
Frequent northeastern quarter; infrequent extreme east and northwest; rare elsewhere

Physalis virginiana
Frequent in Paleozoic Plateau

Carex conn.Close();
Infrequent to frequent throughout

Rhus aromatica
Common southeast; rare northeast

Rorippa austriaca
Rare central and west: Emmet county 1932, Ida county, Page county and Story county

Rosa blanda
Infrequent to frequent throughout

Rhynchospora capillacea
Rare north

Rosa Carolina
Common eastern half; frequent north central; infrequent to rare elsewhere

Rhamnus cathartica
Frequent northern half; rare southeast

Lycopus americanus
Rare northwest: Clay County 1936, and Lyon county 1899

Ratibida columnifera
Common northwest; rare remainder of western half

Rhus copallina
Rare southeast and south central: Davis County 1943, Madison county 1930 and Van Buren county 1940

Rumex crispus
Infrequent south central and southwest; frequent to common elsewhere

Ranunculus cymbalaria
Frequent north central and in lakes area; infrequent to rare rest of western half

Ribes cynosbati
Infrequent to rare northwest and southern half; frequent to common elsewhere

Rhamnus davurica
Rare northeast: Winneshiek county

Rosa eglanteria
Infrequent escape from cultivation in north central, in lakes area and southeast

Ranunculus fascicularis
Common east central; frequent in northeast; rare central and southeast

Ranunculus flabellaris
Common in lakes area; infrequent central and extreme east; rare south central

Rubus flagellaris
Infrequent to rare northern half

Rhamnus frangula
Rare escape from cultivation

Rhus glabra
Common throughout

Carex conoidea
Rare northwest: Dickinson county 1950

Rudbeckia hirta
Common throughout most of state; rare northwest

Ribes hirtellum
Rare southeast: Van Buren county

Rubus hispidus
Rare northeast: Black Hawk County

Ribes hudsonianum
Rare northeast: Allamakee County, Clayton County, Delaware County and Dubuque county

Ruellia humilis
Frequent to common southern half; infrequent to rare northern half

Rubus idaeus
Rare escape from cultivation in southwest, north central and extreme east

Rudbeckia laciniata
Common north central and in Paleozoic Plateau; frequent to infrequent elsewhere

Rhamnus lanceolata
Frequent to common southern half and extreme east; rare or absent elsewhere

Ranunculus longirostris
Common in lakes area; infrequent central, east and in Paleozoic Plateau; rare elsewhere

Reseda luteola
Rare central, and in west central: Harrison county 1930, Ida county and Monona county 1931

Ruppia maritima
Rare northwest: Dickinson county

Juncus greenei
Frequent north central and in lakes area; rare elsewhere

Rumex mexicanus
Not reported southwest; infrequent to rare elsewhere

Ribes missouriense
Common throughout

Poa languida
Frequent to common southern half; rare north

Rumex obtusifolius
Infrequent to rare throughout

Rubus occidentalis
Common throughout

Circaea lutetiana
Rare northeast: Allamakee County

Ribes odoratum
Rare west and south central

Rumex orbiculatus
Infrequent to rare throughout

Rorippa palustris
Infrequent to common throughout

Rosa palustris
Rare southwest: Taylor county

Rumex patientia
Infrequent north and east

Scheuchzeria palustris
Common in lakes area; infrequent north central and northeast; rare southern half

Ratibida pinnata
Frequent to common throughout most of state

Rorippa prostrata
Rare northwest: Emmet county

Robinia pseudoacacia
Frequent to common throughout most of state; often escaping from cultivation

Rubus pubescens
Rare northeast

Rotala ramosior
Rare north, central and east

Raphanus raphanistrum
Rare throughout

Ranunculus recurvatus
Infrequent extreme east; not reported from northwest; rare elsewhere

Ranunculus repens
Rare central, east central and southeast: Des Moines county, Johnson county 1909, Scott county and Tama county

Ranunculus rhomboideus
Infrequent to rare north

Ribes sativum
Rare escape from cultivation

Raphanus sativus
Rare escape from cultivation throughout

Ranunculus sceleratus
Frequent in lakes area; infrequent to rare elsewhere

Ranunculus septentrionalis
Rare northwest; frequent to common elsewhere

Rorippa sessiliflora
Frequent to infrequent throughout most of state; rare in Paleozoic Plateau

Rosa setigera
Rare southwest and southeast

Rorippa sinuata
Rare west, and in northeast, southeast and south central: Black Hawk County 1929, Fremont county 1888, Harrison county 1907, Henry county 1928, Lyon county, Marion county 1898,and Page county

Ruellia strepens
Infrequent to rare southern half

Rubus strigosus
Infrequent northeast, except common in Paleozoic Plateau

Rudbeckia subtomentosa
Apparently absent west central and northwest; rare to infrequent elsewhere

Rorippa sylvestris
Rare throughout most of state; absent northwest and south central

Ranunculus testiculatus
Rare east central and southwest: Cass County and Johnson county

Rudbeckia triloba
Frequent to common eastern two-thirds; infrequent southwest

Rhus typhina
Common in Paleozoic Plateau; rare remainder of northeast; frequent extreme east central

Rumex venosus
Rare northeast and southeast: Des Moines county, Dubuque county 1936

Rumex verticillatus
Frequent eastern half

Rhexia virginica
Rare east central and southeast: Cedar County, Clinton County and Muscatine county

Rosa woodsii
Rare northern half

Sedum acre
Rare northeast: Dubuque county

Equisetum laevigatum
Frequent to common throughout most of state; rare northeast

Plantago cordata
Frequent to common northeastern half; infrequent to rare elsewhere

Salix alba
Infrequent to rare escape from cultivation throughout

Sinapis alba
Rare central and northeast: Chickasaw County 1926 and Story county 1894

Sassafras albidum
Rare southeast: a single station in Lee county

Symphoricarpos albus
Rare northeast: native in Allamakee County, rare escape from cultivation elsewhere

Sisymbrium altissimum
Frequent to common southern half; frequent north central; infrequent to rare elsewhere

Sparganium americanum
Infrequent southeast; rare northeast, south central and southwest

Zanthoxylum americanum
Common throughout

Scirpus americanus
Frequent north central; rare northwest; rare to infrequent southwestern half

Salix amygdaloides
Frequent northeastern quarter; common elsewhere

Sparganium androcladum
Rare east central and southeast: Johnson county, Muscatine county 1922

Sicyos angulatus
Frequent southeast and east; infrequent to rare western two-thirds of state

Eruca sativa
Rare southern half

Sanguisorba annua
Rare escape from cultivation

Silene antirrhina
Infrequent to frequent north; frequent to common south

Shepherdia argentea
Rare west central and northwest: Emmet county, Harrison county, Monona county, Plymouth county and Woodbury county

Sinapis arvensis
Common west; rare in Paleozoic Plateau; infrequent to frequent elsewhere

Sonchus arvensis
Rare eastern quater; infrequent elsewhere

Sonchus asper
Infrequent to rare eastern quater; frequent to common elsewhere

Sporobolus asper
Infrequent to rare northeast; frequent to common elsewhere

Stachys aspera
Rare northeast, east central and south central: Clayton County, Johnson county and Mahaska county

Scirpus atrovirens
Common throughout

Sorbus aucuparia
Occasional escape from cultivation

Senecio aureus
Frequent north central and in Paleozoic Plateau; rare elsewhere

Salix babylonica
Rarely persists from cultivation

Salix bebbiana
Infrequent northeastern quarter; rare north central and extreme e

Sorghum bicolor
Rare escape from cultivation

Agropyron repens X Agropyron trachycaulum
Rare to infrequent eastern half; infrequent to common western half

Sagittaria calycina
Infrequent southwestern two-thirds

Sisyrinchium campestre
Common throughout

Sabatia campestris
Rare east central and southeast: Jackson county 1924 and Lee county 1931

Sanguinaria canadensis
Frequent to common throughout

Sanicula canadensis
Frequent to common throughout

Sambucus canadensis
Common throughout

Solidago canadensis
Frequent to common throughout

Juncus alpinus
Rare northeastern third

Solatium carolinense
Infrequent to rare northeast; common elsewhere

Secale cereale
Infrequent escape from cultivation throughout

Spiranthes cernua
Infrequent eastern two-thirds; rare west central: Harrison county and Woodbury county

Sparganium chlorocarpum
Infrequent north central and in lakes area

Sporobolus clandestinus
Rare southeast: Henry county 1935, Jefferson county 1935 and Muscatine county

Sphaeralcea coccinea
Rare west central, northwest and southwest: Harrison county, Plymouth county and Pottawattamie county

Salsola collina
Rare central: Story county

Cornus amomum
Rare west central and northwest: Harrison county, O'Brien county, Osceola county and Woodbury county

Senecio congestus
Rare north central, northeast and in lakes area

Sagittaria cristata
Rare southeastern two-thirds; frequent in lakes area

Sporobolus cryptandrus
Frequent to common throughout

Silene cserei
Rare eastern half; rare to infrequent northwest

Sagittaria cuneata
Rare northern half except frequent in lakes area

Scirpus cyperinus
Frequent to common northeast; infrequent to rare south

Silene dichotoma
Frequent north central; rare southern half

Salix discolor
Common north central and northeast; infrequent to rare elsewhere

Solatium dulcamara
Infrequent south central; rare north central, extreme east and southeast; spreading throughout

Sclerochloa dura
Rare southwest: Page county

Smilax ecirrhata
Infrequent east; frequent to common elsewhere

Selaginella eclipes
Rare southeast: Muscatine county and Worth county

Sparganium eurycarpum
Rare northeast; frequent to infrequent elsewhere

Salix Candida
Common throughout

Setaria faberi
Infrequent northern half; common southern half

Scolochloa festucacea
Frequent in lakes area; rare north central

Solidago flexicaulis
Not reported from northwest; infrequent in Iowan Surface; frequent to common elsewhere

Scirpus fluviatilis
Frequent to infrequent throughout most of state

Symplocarpus foetidus
Rare e

Saxifraga forbesii
Frequent in Paleozoic Plateau

Salix fragilis
Infrequent to frequent escape from cultivation throughout

Scutellaria galericulata
Common in lakes area; infrequent to rare elsewhere

Setaria geniculata
Rare east central: Jones county

Solidago gigantea
Frequent to common throughout

Senecio glabellus
Rare southwest: Fremont county

Setaria glauca
Common throughout

Stellaria graminea
Rare central, northwest and east: Allamakee County, Emmet county 1923, Hardin county, Jefferson county 1935, Johnson county, Louisa county and Poweshiek county

Sagittaria graminea
Rare southeastern two-thirds; frequent in lakes area

Sanicula gregaria
Infrequent northwest; common elsewhere

Sorghum halepense
Rare escape from cultivation in extreme south

Scirpus hallii
Rare southeast: Louisa county and Muscatine county 1890

Strophostyles helvula
Common southeast and southwest; frequent to infrequent elsewhere

Smilax herbacea
Frequent to common throughout

Scirpus heterochaetus
Infrequent to rare throughout most of state

Sporobolus heterolepis
Common north central and southwest; infrequent elsewhere

Smilax hispida
Infrequent northwest; common elsewhere

Astragalus distortus
Rare in Paleozoic Plateau and extreme east

Salix humilis
Frequent to common throughout

Commelina erecta
Common north central and extreme west; rare to infrequent elsewhere

Scutellaria incana
Rare southeast: Louisa county 1892

Spermolepis inermis
Rare central, northeast and southeast: Dubuque county, Lee county, Marshall county 1929 and Muscatine county

Senecio integerrimus
Rare north central and in lakes area

Silphium integrifolium
Frequent to common southern half; infrequent to rare northeastern quarter

Solatium interius
Rare: Harrison county

Setaria italica
Rare throughout

Spiranthes lacera
Rare north central, east and south central

Silphium laciniatum
Common western half; frequent to infrequent eastern half

Scrophularia lanceolata
Frequent to common north and eastxtreme east; infrequent to rare elsewhere

Scutellaria lateriflora
Common northeastern two-thirds; frequent south central and southwest; rare northwest

Sagittaria latifolia
Common northeastern half; rare to infrequent elsewhere

Strophostyles leiosperma
Frequent to common southern half; infrequent to rare northern half

Scutellaria leonardii
Infrequent to frequent throughout

Sisymbrium loeselii
Rare central and west: Emmet county 1925, Ida county, Monona county, Page county, Plymouth county, Story county and Woodbury county

Yucca glauca
Infrequent north central and south central; rare northeast and southeast

Spiranthes lucida
Rare northeast: Allamakee County

Salix lucida
Rare north

Spiranthes magnicamporum
Rare north central, northeast and south central: Allamakee County, Delaware County, Dubuque county, Floyd county and Marion county

Sanicula marilandica
Common in Paleozoic Plateau and southeast; infrequent to rare northern half

Scrophularia marilandica
Infrequent northwest; frequent to common elsewhere

Scirpus maritimus
Rare northwest: Dickinson county and Palo Alto county 1943

Stellaria media
Rare northeast; common elsewhere

Solidago missouriensis
Common western two-thirds; infrequent to rare east

Scirpus mucronatus
Rare southwest: Page county

Sporobolus neglectus
Frequent north central and southwest; infrequent to rare elsewhere

Solidago nemoralis
Frequent to common throughout most of state; infrequent northwest

Salvia nemorosa
Rare west central and northwest: Dickinson county, Emmet county and Guthrie county

Scutellaria nervosa
Rare east central and southeast: Jefferson county 1930 and Linn county

Salix nigra
Infrequent northwest and extreme east; common elsewhere

Silene nivea
Infrequent in Paleozoic Plateau; rare elsewhere

Silene noctiflora
Infrequent escape from cultivation throughout; common in some areas

Sorghastrum nutans
Common throughout

Schrankia nuttallii
Rare central, west central and southwest: Harrison county 1926, Mills county, Tama county 1895

Sphenopholis obtusata
Frequent to common north central and south central; infrequent to rare elsewhere

Sphenopholis obtusata
Common southeast; rare western quarter; infrequent to frequent elsewhere

Symphoricarpos occidentalis
Common northwest, north central and southwest; infrequent to rare elsewhere

Sisymbrium officinale
Frequent to common southern half; frequent to infrequent northern half

Saponaria officinalis
Frequent to common throughout

Sonchus oleraceus
Frequent southern half, north central and in lakes area; rare extreme east

Symphoricarpos orbiculatus
Common south; rare to infrequent north

Spiranthes ovalis
Rare central, east central, southeast and south central: Henry county, Jackson county, Linn county, Marion county, Muscatine county and Polk county

Scutellaria ovata
Frequent southeast; infrequent to rare northeast, east central and in Paleozoic Plateau

Scirpus pallidus
Infrequent western half

Stachys palustris
Infrequent northwest; frequent to common elsewhere

Onosmodium molle
Rare northwest: Emmet county 1884

Schedonnardus paniculatus
Rare west: Guthrie county 1928, Harrison county, Lyon county, Page county, Plymouth county and Woodbury county

Scutellaria parvula
Common in Paleozoic Plateau; infrequent northwest; frequent elsewhere

Corispermum nitidum
Rare southeast: Muscatine county

Senecio pauperculus
Frequent north central and southeast; rare northeast

Spartina pectinata
Frequent to common throughout

Salix pedicellaris
Rare north central and northeast

Scirpus pedicellatus
Rare east: Muscatine county, Scott county and Winneshiek county 1933

Scirpus pendulus
Frequent to infrequent north central and south; rare northeast

Saxifraga pensylvanica
Frequent northeastern quarter; rare southeast and south central: Marion county and Muscatine county

Salix pentandra
Rarely persists from cultivation

Silphium perfoliatum
Frequent to common throughout most of state; infrequent northwest

Salix petiolaris
Common north central and northeast; rare east central and southeast

Stylisma pickeringii
Rare southeast: Muscatine county

Solidago patula
Rare west and east central: Clay County, Fremont county, Harrison county and Linn county

Senecio plattensis
Infrequent southwest; frequent to common elsewhere

Spirodela polyrhiza
Frequent to common throughout most of state

Silene pratensis
Infrequent south central and southwest; frequent to common elsewhere

Salvia pitcheri
Rare central, west central and north: Clay County 1936, Dickinson county 1949, Emmet county 1882, Hancock county, Monona county, Story county 1907, and Winneshiek county

Solidago ptarmicoides
Absent south central; infrequent to rare elsewhere

Schizachne purpurascens
Frequent in Paleozoic Plateau; rare elsewhere

Salix purpurea
Rare escape from cultivation

Smilacina racemosa
Infrequent northwest; common elsewhere

Physalis pubescens
Rare northeast and east central

Salvia reflexa
Frequent to common western half; infrequent to rare southeastern quarter

Aristida ramosissima
Frequent north central and in lakes area; rare northeast, and in southeast: Muscatine county 1895

Solidago rigida
Infrequent southeast; frequent to common elsewhere

Salix rigida
Frequent to common throughout

Sagittaria rigida
Apparently absent from northwest, southwest and extreme northeast; infrequent elsewhere

Spiranthes romanzoffiana
Rare northwest: Dickinson county and Emmet county

Streptopus roseus
Rare northeast and east central: Allamakee County, Clayton County, Delaware County, Dubuque county, Fayette county, Jackson county and Winneshiek county

Solatium rostratum
Frequent to common western half and southeast; infrequent to rare northeast

Selaginella rupestris
Rare extreme northwest, northeast and southeast

Solidago sciaphila
Frequent to common in Paleozoic Plateau; rare east central: Jackson county and Clinton County

Schizachyrium scoparium
Common throughout

Salix sericea
Rare e

Scirpus smithii
Rare north central and northeast: Cerro Gordo County and Delaware County

Sorbaria sorbifolia
Rare escape from cultivation in northeast: Allamakee County

Stipa spartea
Frequent to common throughout

Solidago speciosa
Common north central; rare southeast; frequent to infrequent elsewhere

Sida spinosa
Infrequent to frequent southern half

Silene stellata
Common northwest and north central; frequent south; rare northeast

Smilacina stellata
Infrequent northwest; common elsewhere

Sium suave
Common in lakes area; frequent to infrequent southern half; rare elsewhere

Sorghum sudanense
Rare escape from cultivation

Sullivantia sullivantii
Rare northeast and east central: Allamakee County, Clayton County, Delaware County, Dubuque county, Fayette county, Jackson county, Jones county and Linn county

Salvia sylvestris
Rare northwest: Dickinson county 1920

Stachys tenuifolia
Common east; infrequent to rare elsewhere

Silphium terebinthinaceum
Rare northeast and east central: Dubuque county and Jackson county

Sedum ternatum
Rare east central: Cedar County 1950

Scirpus torreyi
Rare east central: Clinton County 1878

Staphylea trifolia
Rare northwest and north central; frequent to common elsewhere

Sanicula trifoliata
Common in Paleozoic Plateau; absent elsewhere

Scleria triglomerata
Infrequent to rare eastern half and southwest

Solidago uliginosa
Rare northeast: Allamakee County

Xyris torta
Rare northwest; common elsewhere

Sporobolus vaginiflorus
Frequent to infrequent throughout

Solidago ulmifolia
Frequent to common throughout most of state

Scirpus validus
Rare west central and southwest: Fremont county 1915, Harrison county 1918, Monona county and Woodbury county

Setaria verticillata
Rare northeast; infrequent to frequent elsewh

Lathyrus venosus
Rare central, northwest and northeast: Chickasaw County, Clay County, Emmet county, Fayette county and Grundy county

Sibara virginica
Rare northeast: Winneshiek county

Silene virginica
Rare northeast and central: Black Hawk County 1949 and Boone County 1989

Setaria viridis
Common throughout

Stipa viridula
Rare northern two-thirds, possibly native only in north Loess Hills

Satureja vulgaris
Rare northeast and east central: Allamakee County and Johnson county 1907

Silene vulgaris
Frequent north central; rare south central

Senecio vulgaris
Rare central: Boone County

Syringa vulgaris
Frequent persists from cultivation

Salix X subsericea
Rare northwest: Emmet county

Triticum aestivum
Rare escape from cultivation, not persisting

Tilia americana
Common throughout

Typha angustifolia
Frequent throughout

Thlaspi arvense
Frequent to common throughout

Trifolium arvense
Rare throughout

Torilis arvensis
Infrequent throughout

Triosteum aurantiacum
Infrequent to rare eastern half, except common northeast

Carex richardsonii
Rare east and southwest

Tomanthera auriculata
Rare east and south central

Thaspium barbinode
Frequent eastern half; rare northwestern quarter

Trichostema brachiatum
Common extreme east; infrequent to rare elsewhere

Tradescantia bracteata
Common western two-thirds; rare to frequent northeast; infrequent southeast

Trifolium campestre
Frequent to common north central and south central; infrequent to rare eastern half

Teucrium canadense
Frequent to common throughout

Viola adunca
Infrequent northwest; common elsewhere

Taxus canadensis
Infrequent to frequent northeast and east; rare southeast

Trillium cernuum
Infrequent north central and in Iowan Surface; rare southeast

Tripsacum dactyloides
Infrequent south

Juncus balticus
Common throughout

Trichostema dichotomum
Rare: Madison county 1917

Thalictrum dioicum
Frequent to common northern half; rare in Paleozoic Plateau and south central

Trifolium dubium
Rare east central and southeast: Cedar County, Jefferson county 1935 and Washington county

Tragopogon dubius
Infrequent northeast; common elsewhere

Tridens flavus
Common southeast; infrequent to rare extreme south and along Missouri R.

Trillium flexipes
Common northeast; rare elsewhere

Triadenum fraseri
Rare north and east

Tilia heterophylla
Widely cultivation

Thelypteris hexagonoptera
Rare to infrequent east; rare central: Hardin county 1901

Trifolium hybridum
Frequent to common throughout

Trifolium incarnatum
Rare central, northeast and east central: Dallas County 1924, FA 1898 and Iowa county 1903

Taenidia integerrima
Infrequent to rare throughout

Taraxacum laevigatum
Infrequent to frequent throughout

Typha latifolia
Infrequent to frequent throughout

Triodanis leptocarpa
Rare: Page county

Triglochin maritimum
Rare central and north

Trillium nivale
Rare eastern half; infrequent western half

Tradescantia occidentalis
Rare west central: Woodbury county

Thuja occidentalis
Rare: scattered populations

Taraxacum officinale
Common throughout

Tradescantia ohiensis
Rare northwest but absent in lakes area; frequent to common southeastern two-thirds

Triglochin palustris
Rare northwest and northeast: Chickasaw County, Clay County, Dickinson county, Emmet county, Osceola county and Palo Alto county 1948

Carex muhlenbergii
Frequent northeast; infrequent central and southeast

Talinum parviflorum
Rare northwest: Lyon county

Thymelaea passerina
Rare west: Harrison county, Mills county, Monona county, Plymouth county, Pottawattamie county and Woodbury county

Triodanis perfoliata
Common southeast; infrequent to rare northwestern half

Triosteum perfoliatum
Infrequent northwest; frequent to common elsewhere

Thelypteris phegopteris
Rare northeast and southeast: Allamakee County, Delaware County 1878, Jones county and Muscatine county 1897

Tragopogon porrifolius
Rare north central and southeast

Trifolium pratense
Common throughout

Tragopogon pratensis
Rare northwest and northeast; infrequent elsewhere

Triplasis purpurea
Frequent southeast and southwest; infrequent to rare northeast and extreme east

Toxicodendron radicans
Common throughout

Trillium recurvation
Infrequent to rare east

Trifolium reflexum
Rare east central and south

Trifolium repens
Common throughout

Trifolium resupinatum
Rare southeast: Jefferson county 1935

Thalictrum revolutum
Rare east central and southeast: Des Moines county, Johnson county 1913, Lee county and Scott county

Talinum rugospermum
Rare northeast: Allamakee County

Toxicodendron rydbergii
Frequent to common northern half

Tribulis terrestris
Infrequent southern half; rare northwest: Emmet county, Plymouth county and Sioux county

Thalictrum thalictroides
Frequent to common throughout

Triphora trianthophora
Rare and local northeast and east central

Tephrosia virginiana
Infrequent east; rare northwest and northeast

Tradescantia virginiana
Rare southeast and south central: Davis County 1939, Jefferson county 1935, Keokuk county 1897, Mahaska county 1938, Wapello county 1902 and Washington county

Tanacetum vulgare
Rare escape from cultivation

Typha X glauca
Frequent to common throughout

Ulmus americana
Common throughout

Urtica dioica
Common throughout

Utricularia gibba
Rare east central and southeast: Johnson county and Muscatine county 1878

Uvularia grandiflora
Infrequent northwest and south central; common elsewhere

Utricularia intermedia
Rare northwest: Clay County 1939 and Emmet county 1904

Utricularia minor
Rare northwest and north central: Cerro Gordo County, Dickinson county, Emmet county 1880 and Hancock county

Ulmus pumila
Frequent escape from plantings

Ulmus rubra
Infrequent northwest; frequent to common elsewhere

Uvularia sessilifolia
Rare north central, northeast and southeast

Ulmus thomasii
Infrequent to rare northern half, and in southeast and south central: Decatur County 1900, Lee county 1939, Mahaska county 1928 and Van Buren county 1940

Urtica urens
Rare west central and northeast: Allamakee County 1925 and Carroll County 1921

Utricularia vulgaris
Frequent northwest and north central; infrequent to rare elsewhere

Chenopodium desiccatum
Rare northeast: Allamakee County

Vitis aestivalis
Rare east: Clayton County, Dubuque county, Fayette county, Jackson county, Jones county, Lee county and Louisa county

Veronica agrestis
Rare northwest, and in southwest: Page county

Verbesina alternifolia
Common south central; frequent southeast; rare north central

Veronica americana
Rare northeast and southeast: Allamakee County, Lee county n.d. (ca. 1887), Muscatine county pre-1900 and Winneshiek county

Vallisneria americana
Frequent in Mississippi R.; rare north central and in lakes area

Prunus pensylvanica
Frequent to common northern half; infrequent to rare southern half

Vicia americana
Rare west

Veronica anagallis-aquatica
Rare north and eastast central

Vaccinium angustifolium
Rare northeast and east central: Allamakee County, Clayton County and Jones county

Veronica arvensis
Frequent to common southeast; frequent southwest; infrequent to rare elsewhere

Vernonia baldwinii
Frequent to common southern half; rare north central

Verbascum blattaria
Frequent north central; infrequent southeast and south central; rare northwest

Conium maculatum
Infrequent northeast; frequent to common elsewhere

Verbena canadensis
Rare northeast and south central: Dubuque county, Lucas county and Warren county

Geum aleppicum
Infrequent to rare throughout most of state

Veronica catenata
Frequent in Des Moines lobe; rare or absent elsewh

Vitis cinerea
Rare s

Vicia cracca
Rare northwest: Clay County 1945

Viburnum dentaturn
Infrequent southwestern quarter

Valeriana edulis
Rare northeastern third

Verbesina encelioides
Rare central, west central and northwest: Emmet county 1934, Harrison county 1942, Palo Alto county 1934 and Story county 1934

Vernonia fasciculata
Infrequent northwest and south central; frequent to common elsewhere

Vernonia gigantea
Frequent to infrequent southwestern quarter

Verbena hastata
Common throughout

Viola incognita
Rare northeast and southeast: Allamakee County, Muscatine county 1935 and Winneshiek county

Viola lanceolata
Rare east: Benton County, Buchanan County, Cedar County, Johnson county, Jones county, Linn county, Scott county and Muscatine county 1923

Viburnum lentago
Frequent to infrequent southern half; rare northwest; common elsewhere

Verbascum lychnitis
Rare south central: Madison county 1917

Coreopsis grandiflora
Rare east, and in northwest: Dickinson county

Vinca minor
Rare escape from cultivation

Viola missouriensis
Frequent extreme east; infrequent to rare in remainder of eastern half

Viola missouriensis
Rare central, east central and southeast: Benton County, Boone County, Clinton County, Jefferson county 1933, Story county and Van Buren county

Vernonia missurica
Frequent southeast; rare northwest

Viburnum molle
Rare southeast and southwest: Henry county, Jefferson county, Pottawattamie county and Van Buren county

Vaccinium myrtilloides
Rare northeast: Allamakee County and Clayton County

Viola nephrophylla
Infrequent throughout much of state; rare north central and southwest

Viola nephrophylla
Rare east central: Clinton County, Johnson county

Valeriana officinalis
Rare escape from cultivation

Veronica officinalis
Rare east central: Clinton County

Viburnum opulus
Rare escape from cultivation

Viola pedata
Common in Paleozoic Plateau; frequent southwest; infrequent elsewhere

Hepatica nobilis
Common northwest and north central; frequent to infrequent elsewhere

Veronica peregrina
Rare northwest; frequent to common elsewhere

Veronica persica
Rare northwest and east: Chickasaw County 1926, Johnson county 1926, Sioux county and Van Buren county

Verbascum phlomoides
Rare east, and in central and west central: Polk county and Sac county

Viola pratincola
Infrequent northwest and extreme east; frequent to common elsewhere

Viola pratincola
Rare central, west central, northwest and e

Viburnum prunifolium
Rare central, east central, southeast and southwest: Jackson county, Johnson county, Lee county, Poweshiek county, Taylor county and Van Buren county

Viola pubescens
Absent northwest and north central; rare to infrequent elsewhere

Vaccaria pyramidata
Infrequent southwest; rare north central

Viburnum rafinesquianum
Common northeast; frequent southeast; infrequent to rare western half

Viola rafinesquii
Rare central, southeast and south central

Viola renifolia
Rare northeast: Allamakee County, Clayton County, Dubuque county and Winneshiek county

Vitis riparia
Common throughout

Viola sagittata
Rare to infrequent east and south central; rare northwest: Lyon county 1896

Viola sagittata
Rare east central and southeast: Johnson county and Muscatine county

Vicia sativa
Rare east central: Scott county

Solidago riddellii
Frequent in Paleozoic Plateau; rare remainder of northeast and north central

Veronica scutellata
Rare east central: Clinton County

Veronica serpyllifolia
Infrequent east

Verbena simplex
Frequent northeast and extreme east; infrequent southeast; rare central and northwest: Story county and Lyon county 1928

Viola sororia
Common throughout

Viola striata
Rare southeast: Jefferson county and Van Buren county

Verbena stricta
Common throughout

Verbascum thapsus
Common throughout

Viola tricolor
Rare escape from cultivation

Viburnum trilobum
Frequent in Paleozoic Plateau

Verbena urticifolia
Frequent to common throughout

Viola viarum
Rare southern half

Vicia villosa
Infrequent to rare throughout most of state

Veronicastrum virginicum
Infrequent northwest; common elsewhere

Vitis vulpina
Rare central, southeast and south central: Decatur County 1942, Lee county, Mahaska county, Poweshiek county and Van Buren county

Veratrum woodii
Rare south

Viola X bernardii
Rare central, north central, east and south central

Verbena X blanchardi
Rare northeast and southwest: Black Hawk County and Cass County

Verbena X deamii
Rare northeast: Allamakee County

Verbena X engelmannii
Rare southeast: Louisa county, Muscatine county and Van Buren county

Verbena X moechina
Rare east: Black Hawk County 1930, Clinton County, Jones county and Muscatine county 1929

Viola X napae
Rare central and southeast: Story county 1946 and Muscatine county 1924

Verbena X rydbergii
Rare northwest, northeast, southeast and south central: Black Hawk County, Decatur County, Dickinson county, Louisa county 1927 and Muscatine county

Viola X sublanceolata
Rare east central and southeast: Jones county and Muscatine county 1935

Wolffia columbiana
Common in lakes area; infrequent to rare elsewhere

Wisteria frutescens
Rare escape from cultivation in central: Boone County and Hardin county

Woodsia ilvensis
Rare northeast: Allamakee County and Winneshiek county

Woodsia obtusa
Infrequent to frequent east; rare central and south central

Camelina microcarpa
Rare northwest and northeast: Allamakee County, Lyon county and Winneshiek county

Wolffia punctata
Infrequent to rare northeastern half

X Agrohordeum macounii
Frequent northwest; rare southwest

Teucrium canadense
Rare central: Story county

X Elyhordeum montanense
Rare north central: Humboldt county 1896

Dryopteris triploidea
Rare northeast: Allamakee County, Clayton County and Dubuque county; discovered 1979

Xanthium spinosum
Rare central: Story county and Dallas County

Xanthium strumarium
Frequent to common throughout

Crataegus succulenta
Rare east: Benton County, Buchanan County, Cedar County, Fayette county 1894, Linn county and Muscatine county

Bidens connata
Frequent to common in Loess Hills

Ranunculus pensylvanicus
Common throughout

Zizia aptera
Infrequent to rare northern half; not reported elsewhere

Zizia aptera
Rare northwest and northeast: Delaware County and Emmet county

Zizania aquatica
Rare: scattered in northern two-thirds

Zizia aurea
Frequent to common throughout

Zigadenus elegans
Infrequent north

Zigadenus glaucus
Rare northeast

Zea mays
Infrequent escape from cultivation, not persisting

Zannichellia palustris
Frequent in lakes area; infrequent northeastern quarter; rare southeast: Muscatine county 1894