TREATMENT FROM THE JEPSON MANUAL (1993) |
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©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora. |
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Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1many 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)45; stamens 45, 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):128. See glossary p. 25 for illustrations of general family characteristics.
Annual
Stems prostrate to erect, often rooting below, simple to much-branched
Leaves simple, opposite, sessile
Inflorescence: heads radiate, small, solitary or in small cymes; peduncles short or 0; involucre hemispheric; phyllaries in 12 ± equal series, free, ovate; receptacle rounded, chaffy, scales narrowly linear, bristle-like
Ray flowers many; corollas white; ligules short, narrowly linear
Disk flowers many; corollas white; style branches very short, included; anthers brown, included
Fruit 4-angled, ± flat, brown, glabrous; pappus a crown of minute bristles or 0
Species in genus: 4 species: especially tropical
Etymology: (Greek: deficient, from absence of pappus)