Annuals. Stems 0 or 1 (erect, 0-5 cm). Leaves mostly erect, sometimes prostrate; petioles not purplish, margins glabrous or ciliate; blades usually oblanceolate to spatulate, rarely linear, 1-25 cm, margins entire or lobed; lobes 2-3 pairs, linear to spatulate, spreading to antrorse, lobules mostly 0, glabrous or densely hairy. Peduncles elongating after flowering, 3-60 cm in fruit, glabrous or glabrate, or basally puberulent and apically hairy to tomentose, sometimes stipitate-glandular. Involucres cylindric to hemispheric, 1-2 cm in fruit. Phyllaries in 2-3 series, green or medially rosy purple, sometimes purple-black spotted or tipped, subequal to unequal, margins glabrous or ciliate, faces usually puberulent to villous, mostly stipitate-glandular, sometimes glabrous; outer erect or spreading, adaxially usually villous to lanate, sometimes glabrous; inner erect, ± elongating after flowering. Receptacles epaleate. Florets 5-100(-300); corollas yellow, tubes 1-5 mm, ligules 2-15 × 1-3 mm; anthers 1-4 mm. Cypselae 7-16 mm, bodies mostly fusiform to obconic, sometimes tumid, 2-5(-10) mm, beaks 5-11 mm, lengths 1-4 times bodies, ribs 0 or alate, straight to strongly undulate, uniform or diminishing proximally; pappus bristles in 2-3 series, 4-9 mm.

FNA 2006, Wiggins 1964, Kearney and Peebles 1969

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Annual from slender taproot.  Leaves: Oblong, spatulate or linear, entire, denticulate or sinuate-pinnatifid, 0.2-3 cm wide, 5-15 cm long, sparsely villous or glabrous, lobes on pinnatifid blades ovate to oblong, spreading or ascending, nearly as wide as long. Flowers: Slender scapes 5-40 cm tall, often several from single root, glabrous or very sparsely villous, involucres 10-18 mm high, often nearly as broad, bracts lance-acuminate, inner ones glabrous and hyaline-margined, outer ones shorter and arachnoid-villous to glabrate; inconspicuous ligules, barely surpassing involucres and withering early; yellow corolla. Fruits: Fusiform cypselae, body smooth or longitundinally 10-ribbed, 3-4 mm long, glabrous to villosulous, slender beak 5-8 mm long; pappus bristles white, 5 mm long. Ecology: Found on grassy hillsides and openings in brush from 2,500-5,000 ft (762-1524 m); flowers March-May. Notes: Overlaps with A. glauca in the transition zones of the southwestern US. Ethnobotany: Unknown for this species, other species in this genera have medicinal and edible uses. Etymology: Agoseris is from Greek name for goat chicory, heterophylla means the leaves are different on the same plant. Synonyms: Troximon chilense, Troximon heterophyllum Editor: SBuckley, 2010