Agoseris heterophylla
Annual agoseris
(c) Alexander Wentworth, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Native
Agoseris heterophylla (Annual agoseris) is a native California herb in the Asteraceae family, recognized by The only annual *Agoseris* here; slender, taprooted, basal + cauline leaves.
Annual agoseris is a California native annual found in various bioregions, typically growing in open grasslands and disturbed areas. Flowering from March to June, this plant produces bright yellow flowers in heads 10 to 25 millimeters long, with distinctive green or rosy-purple involucre bracts. Growing 5 to 60 centimeters tall with generally erect stems, it develops from a delicate annual habit. Its basal leaves are oblanceolate, ranging 1 to 25 centimeters long, often with entire or pinnately lobed edges, and can be glabrous or covered in white-opaque hairs. The fruit is characterized by a slender 5 to 11 millimeter beak, with the seed body 2 to 5 millimeters long and varying from fusiform to slightly inflated.
Identification and appearance
Key characters: The only annual *Agoseris* here; slender, taprooted, basal + cauline leaves
How to tell it apart
vs Taraxacum: Agoseris bracts graduate gradually in size; Taraxacum has dramatically smaller outer bracts and longer one-sided pappus.; vs Hypochaeris: Agoseris has completely bractless stems; Hypochaeris often has small leafy bracts partway up the stem.; vs Microseris: Agoseris pappus bristles evenly distributed; Microseris has 5-80 white scales (not plume-like bristles).; vs Uropappus: Agoseris has plume-like bristles; Uropappus has 5 large silvery scales alternating with 5 smaller ones.; vs Leontodon: Agoseris has unbranched scapes; Leontodon often has branched stems with multiple heads.
Frequently asked questions
Is Agoseris heterophylla native to California?
Yes. Agoseris heterophylla is native to California (recorded as native).
What plant family does Agoseris heterophylla belong to?
Agoseris heterophylla is in the Asteraceae family, genus Agoseris.
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.