Helianthus petiolaris, Prairie Sunflower
Scientific Name: Helianthus petiolaris
Common Name: Prairie Sunflower
Also Called: Plains Sunflower, Sunflower, (Spanish: Girasol)
Family: Asteraceae, Sunflower Family
Synonyms: (Helianthus niveus ssp. canescens, Helianthus canescens, Helianthus canus)
Duration: Annual, taproot
Size: 4 to 6 feet but may reach 9 feet.
Growth Form: Shrub; erect with many branching stems, glaucous or rough, hairy.
Leaves: Green or bluish-green; opposite below, alternate above, petiolate, lanceolate, glabrous or rough, hairy.
Flower Color: Yellow; showy radiate heads borne terminally on 3 or 4 inch peduncles, green linear bracts (phyllaries) subtend each head, ray flowers yellow, 10 to 30, disk florets numerous, reddish-brown, seed an achene.
Flowering Season: March to October.
Elevation: 500 to 7,500 feet.
Habitat Preferences: Sunny open areas, sandy or gravelly areas, roadsides and disturbed areas, dry or moist areas.
Recorded Range: Much of the United States and Canada and south into northern Mexico. Found in the northern and southern portions of Arizona.
North America & US County Distribution Map for Helianthus petiolaris.
U.S. Weed Information: Helianthus petiolaris is included in Weeds of the United States and Canada. Plants included here may become weedy or invasive.
Invasive/Noxious Weed Information: No data available,
Wetland Indicator: No data available,
Threatened/Endangered Information: No data available.
Genus Information: 62 species in Helianthus throughout North America and Canada. 8 species are found in Arizona;
2 subspecies in Helianthus petiolaris
Helianthus petiolaris ssp. petiolaris, Prairie Sunflower found throughout the range listed above and
Helianthus petiolaris fallax which is native to 5 southwestern states; AZ, UT, NM and smaller populations in NV and CO.
Comments: The large bright attractive flowers are visited frequently by many insects and the seeds readily attract birds. Prairie Sunflower is similar in appearance to the Common Sunflower, Helianthus annuus which generally has much larger leaves. Both of these beautiful species are often considered weeds.
Several uses have been identified for Helianthus petiolaris, powdered leaves alone or in ointment were used on sores and swellings and the plant was used as spider bite medicine. See species account from Native American Ethnobotany, University of Michigan, Dearborn.