Asteraceae
Daisy Family
Helianthus tuberosus L.
- Notes: Helianthus tuberosus is similar to H. grosseserratus except the stem is rough and the leaves are shorter and wider (4” by 1 1/2”). The marginal leaf teeth are not quite as large, and the leaves are often alternate rather than opposite in the inflorescence. Usually there are more flower heads forming a corymbiform inflorescence. The stalks below the heads are very hairy. The fillaries are similar except H. tuberosus has stiff marginal hairs and oppressed hairs on the lower (outer) surfaces. H. tuberosus has shallow, horizontal rhizomes with swellings (tubers) several inches long and often grows in large patches. Flowering is from mid-August to mid-September, and fruiting begins in late August. H. tuberosus is frequently found on low, moist prairies, or on roadsides, and in unmanaged places.
- Bibliography from Biodiversity Heritage Library
- Vascular Plants of Iowa
Can be found in these counties:
