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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



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.


Theodore M. Barkley

Annual to low, dense subshrub (< 40 cm diam in CA), much-branched, ± hairy and scaly; odor turpentine-like
Leaves alternate, hairy; blade ± ovate to reniform
Inflorescence: heads discoid, peduncled in axils; involucre ± obconic; phyllaries in 2 series; receptacle flat, naked
Disk flowers 9–50; corollas cylindric, in CA light yellow and often fading reddish, glandular, ± soft-hairy; anther bases ± sagittate, tips acute to blunt; style branches ± shaggy-papillate, ± truncate or with tapered appendage
Fruit cylindric to obconic, weakly 10-ribbed, densely hairy in CA; pappus of many bristles in 1–4 series
Species in genus: 5 species: sw North America
Etymology: (Greek: brittleness, from stems)
Reference: [Strother 1978 North America Fl II 10:142–146]


P. annua (Nutt.) A. Gray

Stems often purplish
Leaves short-petioled; blade 8–16 mm, generally ± toothed upward, (gray-)green
Inflorescence: outer phyllaries 4–5 mm, erect; inner phyllaries generally 8 or 13
Flowers 13–16; corollas 4–4.5 mm
Fruit ± 2.5 mm; pappus bristles 35–50 in 1 series, coarse, red-brown
Chromosomes: 2n=34
Ecology: Dry, sandy shadscale scrub, alkali flats
Elevation: generally 800–2000 m.
Bioregional distribution: East of Sierra Nevada, Mojave Desert
Distribution outside California: to Idaho, Utah, nw Arizona
Flowering time: Jun–Oct

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