|Jepson Flora Project: Jepson Interchange|
|TREATMENT FROM THE JEPSON MANUAL (1993)||
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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
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 to subshrubs, generally ± hairy
Leaves alternate or basal, generally petioled, reduced upward, entire and linear or generally elliptic to ovate or obovate and 14-pinnately lobed; 1° lobes longest near middle or base of blade
Inflorescence: heads discoid (but outer flowers often enlarged, ± ray-like), 1many per stem, generally in terminal cymes; peduncle generally hairy like phyllary bases; involucre generally < 15 mm diam, cylindric to obconic or hemispheric; phyllaries in 12 ± equal series, generally linear to lanceolate, tips generally ± flat, generally ± green; receptacle flat to rounded, generally naked
Flowers 10many; corollas radial (outer, if enlarged, ± bilateral), generally white to pinkish or yellow, generally opening in daytime; anthers generally exserted
Fruit club-shaped, generally not compressed, stiffly hairy; pappus 0 or of 420 fringed scales in 1few series
Species in genus: 18 species: w North America
Etymology: (Greek: gaping ray, from enlarged outer corollas of some)
Reference: [Mooring 1980 Amer J Bot 67:13041309]
Spp. of sect. Chaenactis hybridize.
Stems generally 1few, erect to spreading, < 50 cm; hairs thinning with age
Leaves < 11 cm, ± cobwebby, fleshy or not; largest entire or 12-pinnately lobed, 1° lobes 17 pairs, longest near blade middle, tips flat to curled or cylindric
Inflorescence: heads 1several per stem; peduncle < 20 cm; involucre widely cylindric to obconic or hemispheric, generally ± tomentose or glandular-hairy; longest phyllaries 4.59 mm, tips erect, ± rigid, generally blunt
Flowers: corollas ± bright to deep yellow, outer bilateral, greatly enlarged, inner radial, 48 mm
Fruit 39 mm; pappus scales (1)48 in 12 series, scales of outer fruit generally < inner, unequal, scales of inner fruit generally equal, longest 18 mm
Ecology: Generally dry open places, sometimes dunes or serpentine
Elevation: < 1600 m.
Bioregional distribution: North Coast Ranges, Sierra Nevada Foothills, Tehachapi Mountain Area, Great Central Valley, Central Western California, Southwestern California, w edge Desert
Distribution outside California: n Baja California
Highly variable; some forms like C. stevioides except flower color.