|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.
Species in genus: 1 sp
Etymology: (Greek: double pappus)
Reference: [Porter 1943 Amer J Bot 30:481483]
Stems much-branched, widely spreading to ascending, generally < 6 dm, striate, smooth, white above, grayish below; leafless stems spiny
Leaves short-petioled, generally < 2 cm, obovate or elliptic, entire, sometimes ± thick, light yellow- or gray-green
Inflorescence: heads radiate, in crowded, flat-topped clusters generally 35 cm wide; involucres cylindric, ± 5 mm, < 3 mm wide; phyllaries 712, ovate, whitish or pale green
Ray flowers 12, barely > involucre, tips 2- or 3-toothed, yellow
Disk flowers 37, staminate; corollas narrowly funnel-shaped, sinuses deep, lobes reflexed, style-branch appendages lanceolate to rounded
Fruit of ray flowers < or = 3 mm, hairy; pappus of 1520 stout bristles fused at base, generally 1 mm; ovary of disk flowers < or = 1 mm, glabrous; pappus of 25 flattened, twisted bristles generally < or = 3 mm
Ecology: Rocky or gravelly flats, slopes, canyons
Elevation: < 1600 m.
Bioregional distribution: c&e Mojave Desert
Distribution outside California: to Utah, Nevada, Arizona
Varieties not known to intergrade.
Leaves glabrous, sometimes gummy
Habitats of sp.
Bioregional distribution: ne Mojave Desert
Distribution outside California: Nevada
Flowering time: AprMay