Helianthus petiolaris
Prairie sunflower
(c) Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger · licence
Family: Asteraceae · Type: Herb · Native
Helianthus petiolaris (Prairie sunflower) is a native California herb in the Asteraceae family.
Prairie sunflower is a California native annual found in open grasslands and disturbed areas across western North American plains and valleys. Flowering from July to October, this plant produces bright yellow ray flowers surrounding a disk of red to purple flower centers, creating large sunflower heads 15 to 25 millimeters in diameter. Growing with erect stems 40 to 200 centimeters tall, covered in stiff gray or white hairs, the plant develops a distinctive branching structure. Its leaves are mostly alternate, with blades 4 to 15 centimeters long, lance-shaped to widely ovate, having wedge-shaped or slightly heart-shaped bases and entire or slightly toothed margins. The plant produces small fruits 3 to 4.5 millimeters long, characteristic of sunflower species.
How to tell it apart
vs Encelia: Helianthus is herbaceous with soft stems; Encelia is a woody shrub with persistent branches.; vs Bahiopsis: Helianthus has soft herbaceous stems; Bahiopsis is woody-based with persistent woody stems.; vs Wyethia: Helianthus has smaller disk flowers and readily falling seed scales; Wyethia has very large 8-12mm disk flowers.; vs Rudbeckia: Helianthus has a flat or rounded yellow center; Rudbeckia has a tall dark cone-shaped center.; vs Venegasia: Helianthus dies back to ground level; Venegasia is a large evergreen shrub in shaded canyons.
Frequently asked questions
Is Helianthus petiolaris native to California?
Yes. Helianthus petiolaris is native to California (recorded as native).
What plant family does Helianthus petiolaris belong to?
Helianthus petiolaris is in the Asteraceae family, genus Helianthus.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.