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.

PSATHYROTES

Theodore M. Barkley

Annual to low, dense subshrub (< 40 cm diam in CA), much-branched, ± hairy and scaly; odor turpentine-like
Leaves alternate, hairy; blade ± ovate to reniform
Inflorescence: heads discoid, peduncled in axils; involucre ± obconic; phyllaries in 2 series; receptacle flat, naked
Disk flowers 9–50; corollas cylindric, in CA light yellow and often fading reddish, glandular, ± soft-hairy; anther bases ± sagittate, tips acute to blunt; style branches ± shaggy-papillate, ± truncate or with tapered appendage
Fruit cylindric to obconic, weakly 10-ribbed, densely hairy in CA; pappus of many bristles in 1–4 series
Species in genus: 5 species: sw North America
Etymology: (Greek: brittleness, from stems)
Reference: [Strother 1978 North America Fl II 10:142–146]