ASTERACEAE

SUNFLOWER FAMILY

David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.

ANISOCOMA

SCALE BUD

G. Ledyard Stebbins

Species in genus: 1 sp.: sw US, n Mex
Etymology: (Greek: unequal pappus)

Native

A. acaulis Torr. & A. Gray

Annual; sap milky
Leaves all basal, 3–5 cm, pinnately lobed; lobes toothed, ± hairy
Inflorescence: head ligulate, solitary, 2–3 cm; peduncle 5–20 cm, glabrous; phyllaries papery-transparent on margins, often with reddish tips and dots, in several series, outer short, oblong, blunt, inner linear, pointed; receptacle with long, narrow chaff scales
Flowers many; ligules pale yellow, readily withering
Fruit 10–15-veined; pappus of plumose bristles in 1 series, white, those on inner side of achene < on outer
Chromosomes: 2n=18
Ecology: Sandy washes, dry slopes
Elevation: 600–2400 m.
Bioregional distribution: s Sierra Nevada, Tehachapi Mountain Area, San Joaquin Valley, South Coast Ranges, Transverse Ranges, Peninsular Ranges, Great Basin Floristic Province, Desert
Distribution outside California: Nevada, Arizona, Baja California
Flowering time: Apr–Jun
Horticultural information: TRY.