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.

MALACOTHRIX

W.S. Davis

Annual or perennial herb < 60 dm, generally ± branched, generally erect; sap milky
Leaves generally basal and cauline, alternate, sessile, generally reduced upward
Inflorescence: heads ligulate, 2–10 mm diam; involucre 5–20 mm, generally bell-shaped; phyllaries in 3–6 series; receptacle naked or with fragile bristles < 5 mm
Flowers: corollas readily withering; ligules yellow or white, generally ± purple-striped below
Fruit generally fusiform, straw-colored to purple-brown, truncate; veins 15 (5 generally prominent, 10 sometimes obscure); outer pappus ± 0 or of 0–6 smooth, persistent bristles, inner 12–32 bristles fused at base, readily deciduous, minutely barbed below
Species in genus: 21 species: w North America, s South America
Etymology: (Greek: soft hair)
Reference: [Williams 1957 Am Midland Naturalist 58:494–517]

Native

M. clevelandii A. Gray

Annual 4–36 cm, glabrous
Leaves: basal not fleshy, generally (ob)lanceolate, teeth or short lobes ± equal, well spaced; cauline much reduced, upper 2–4-toothed at base
Inflorescence: heads 2.5–3.5 mm diam; involucre 5–8.7 mm; outer phyllaries ± 1/2 inner, generally lanceolate
Flowers: corollas 4.6–7.7 mm, pale yellow, outer corollas exserted 1–3 mm
Fruit 1.2–1.8 mm, ± light brown; veins ± equal, extending to very tip; outer pappus teeth needle-like, bristle 1
Chromosomes: 2n=14
Ecology: Cleared areas (burns, slides), generally chaparral
Elevation: < 2100 m.
Bioregional distribution: Northwestern California, Sierra Nevada Foothills, San Joaquin Valley, Central Western California, n Channel Islands (Santa Rosa Island)
Distribution outside California: to Utah, Mexico
Horticultural information: TRY.