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.

SCHKUHRIA

Annual, perennial herb
Stems often much-branched
Leaves simple or pinnately divided, generally gland-dotted; lower opposite; upper alternate
Inflorescence: heads radiate or discoid, in open cymes; peduncles short to long; involucre obconic to bell-shaped; phyllaries 4–18, oblanceolate to obovate, obtuse, margins scarious; receptacle rounded, naked
Ray flowers 0–3; corollas yellow or white; ligules short, inconspicuous
Disk flowers few–many; corollas yellow; style tips acute, triangular
Fruit narrowly obpyramidal, generally 4-angled; angles hairy; pappus generally of 8 scales
Species in genus: 6 species: s North America, n South America
Etymology: (C. Schkuhr, 1741–1811, German botanist)
Reference: [Heiser 1945 Ann Missouri Bot Gard 32:265–278]