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. sonchoides (Nutt.) Torr. & A. Gray

Annual 6–40 cm, ± glabrous
Stem glaucous
Leaves: basal obovate, ± fleshy, ± equally and widely 6–16-lobed; cauline widely lobed at base
Inflorescence: heads 4–6 mm diam; involucre 7–13 mm; outer phyllaries ± 1/2 inner, ovate, margins sometimes with tack-shaped hairs
Flowers: corollas 10–14 mm, lemon yellow, outer corollas exserted 6–10 mm
Fruit 1.8–3 mm, dark or red-brown; outer pappus a scarious, rounded-toothed crown, bristles 0
Chromosomes: 2n=14
Ecology: Generally deep, sandy soils
Elevation: 400–1400 m.
Bioregional distribution: East of Sierra Nevada, Mojave Desert
Distribution outside California: to Wyoming, New Mexico
Flowering time: Apr–Jun
Horticultural information: TRY.