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.

LASTHENIA

GOLDFIELDS

Robert Ornduff

Annual, perennial herb, glabrous or hairy
Stem generally branched, generally erect, < 60 cm
Leaves opposite, < 20 cm, entire to pinnately cut
Inflorescence: heads radiate, solitary or in cymes; phyllaries in 1 or 2 series, free or partly fused; receptacle narrowly conic to hemispheric, naked, smooth, pitted, or rough
Ray flowers 4–21; ligules generally yellow
Disk flowers generally many; corollas generally 5-lobed, generally yellow; anther tips acuminate to triangular; style tips triangular or round, generally hair-tufted
Fruit < 5 mm, cylindric to obovoid, black or gray; pappus of awns, scales, or 0
Species in genus: 17 species: w North America, Chile
Etymology: (Greek: female pupil of Plato)
Reference: [Ornduff 1966 Univ Calif Publ Bot 40:1–92]
Generally self-incompatible (cross-pollinated).

Native

L. burkei (Greene) Greene

BURKE'S GOLDFIELDS

Annual < 30 cm
Stem simple or freely branched, hairy
Leaves < 5 cm, linear, entire or pinnately lobed, glabrous to ± hairy
Inflorescence: involucre 4–6 mm, dome-shaped or obconic; phyllaries 7–16, free, hairy; receptacle dome-shaped or conic, glabrous or hairy
Ray flowers 8–13; ligules < 6 mm
Disk flowers many; anther tips linear to ± ovate; style tips triangular
Fruit < 1.5 mm, club-shaped, hairy; pappus generally of 1 long awn and many short scales
Chromosomes: 2n=12
Ecology: Vernal pools, wet meadows
Elevation: < 500 m.
Bioregional distribution: s Inner North Coast Ranges (s Mendocino, s Lake, and ne Sonoma cos.)
Horticultural information: In cultivation.