Agoseris grandiflora
Bigflower agoseris
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Family: Asteraceae · Type: Herb · Native
Agoseris grandiflora (Bigflower agoseris) is a native California herb in the Asteraceae family.
Bigflower agoseris is a California native perennial herb found in open grasslands and meadows, typically growing from low to mid-elevation regions. Flowering from April to June, this plant produces bright yellow flowers with long, prominent ligules that nearly match the height of the flower head. Growing 25 to 100 centimeters tall with an erect habit, it develops distinctive purple-tinged petioles and leaves with 3 to 5 pairs of lobes angled toward the leaf tip. Its leaves are sparsely to densely hairy, with white-opaque hairs giving the foliage a soft, textured appearance. The fruit develops a thread-like, flexuous beak that can be up to three to four times the length of the seed body, creating a distinctive silhouette in grassland environments.
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 grandiflora native to California?
Yes. Agoseris grandiflora is native to California (recorded as native).
What plant family does Agoseris grandiflora belong to?
Agoseris grandiflora is in the Asteraceae family, genus Agoseris.
Related species
Other California species in the same genus, family, or bioregion.
- Agoseris grandiflora var. grandiflora — Giant mountain dandelion
- Agoseris grandiflora var. leptophylla — Giant mountain dandelion
- Agoseris heterophylla — Annual agoseris
- Agoseris heterophylla var. cryptopleura — Mountain dandelion
- Agoseris heterophylla var. heterophylla — Annual agoseris
- Agoseris hirsuta — Woolly goat chicory
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.