Helianthus petiolaris is an annual herb, similar to H. annuus but smaller, less than 1 m tall.
Leaves stiffly hairy, pale.
Flowers yellow, disk dark, 1-2.5 cm wide, scales between disk fflowers white-bearded at tips, basal bracts narrow, tapering to tip; blooming and fruiting June-Sept.
Fruit 1-seeded achene.
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Origin: Midwestern US.
Habitat: Open, sandy soil.