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.

UROPAPPUS

SILVER PUFFS

Kenton L. Chambers

Species in genus: 1 sp
Etymology: (Latin: tailed pappus, from awn-tipped scales)

Native

U. lindleyi (DC.) Nutt.

Annual 5–70 cm, ± scapose; sap milky
Leaf 5–30 cm, ± basal, ± linear, long-tapered, entire to narrowly lobed, ± soft-hairy (especially petiole base)
Inflorescence: head, ligulate solitary, erect; involucre 10–40 mm, glabrous; phyllaries narrowly lanceolate, outer progressively shorter; receptacle naked
Flowers 5–many; corollas yellow (often reddish below), readily withering, < or = involucre
Fruit 7–17 mm, slender, tapered to tip in CA, obscurely 10-ribbed, generally blackish; outermost fruits scabrous; pappus scales 5, 5–15 mm, deciduous, smooth, silvery, bristle-tip 4–6 mm, slender, smooth, from notched scale tip
Chromosomes: 2n=18
Ecology: Common. Open grassland, woods, chaparral, deserts, generally in loose soils
Elevation: < 1800 m.
Bioregional distribution: California (except North Coast)
Distribution outside California: to Washington, Idaho, Utah, w Texas, n Mexico
Flowering time: Apr–May
Synonyms: Microseris l. (DC.) A. Gray; M. linearifolia (DC.) Sch.Bip
With annual Microseris species a parent of Stebbinsoseris
Horticultural information: TRY.