Asteraceae
Daisy Family
Bigtooth sunflower
Helianthus grosseserratus Martens
- Stem: perennial; 4’ to 6’ tall; unbranched; smooth.
- Leaves: opposite below, sometimes alternate above; oval with rounded bases and sharp tips; 5” by 3/4”; tapering to short leaf stalks; large teeth on the margin, six to ten per inch; appressed hairs below, bulb-based hairs above, slightly rough.
- Inflorescence: several heads on branching stalks from stem tip and upper leaf axils.
- Heads: yellow rays 1” by 3/8”; head 2 1/2” across; disk flowers yellow; fillaries lance-shaped with hairy margins, 1/2” long, reflexed; flowering from mid-August to mid-September.
- Fruits: “seeds” (fruits) 1/8” long; fruiting begins in early September.
- Habitat: frequent on moist prairies and in other open sites such as roadsides, less common in drier sites.
- Bibliography from Biodiversity Heritage Library
- Vascular Plants of Iowa
Can be found in these counties:
