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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.


Perennial from stout rhizome, ± dioecious
Stems erect, appearing before leaves
Leaves: basal, large, long-petioled, blades wide; cauline generally sheathing, scale-like
Inflorescence: heads disciform or weakly radiate, in raceme-like to ± flat-topped clusters; involucre ± cylindric to bell-shaped; main phyllaries in 1 series, equal; receptacle flat, naked
Pistillate flowers 0–few in staminate heads, many in pistillate heads; corollas of 2 kinds, white to pale yellow, sometimes purplish, outer often with short ligules, inner cylindric
Disk flowers staminate, 0–few at center of pistillate heads, many in staminate heads; corollas white to pale yellow, sometimes purplish; anther bases entire or short-sagittate, tips acute; style tips slightly thickened, entire or slightly lobed; pappus reduced
Fruit cylindric, 5–10-ribbed; pappus bristles many
Species in genus: 15 species: North America, Eurasia
Etymology: (Greek: broad-brimmed hat, from large leaves)
Reference: [Cronquist 1978 North America Fl II 10:174–179]


P. frigidus (L.) Fr. var. palmatus (Aiton) Cronquist


Stem 2–6 dm
Leaves: basal blade 10–40 dm wide, ± round to reniform, lobes palmate, coarsely toothed or again pinnately lobed, (sub)glabrous above, sometimes loosely tomentose below
Inflorescence: bracts 2–6 cm, entire to serrate, parallel-veined; heads generally 10–20; involucre 5–9 mm, bell-shaped, often purplish; phyllaries linear
Pistillate flowers: outer corollas with tube 4–6 mm, ligules 2–7 mm, white to pale pink; inner corollas 3–5 mm, cylindric
Disk flowers: corollas 3.5–5 mm, white to pale pink
Fruit 3–4.5 mm; pappus 6–13 mm
Chromosomes: 2n=60,61,62
Ecology: Forests, generally wet soil
Elevation: < 400 m.
Bioregional distribution: Northwestern California, nw&nc Central Western California
Distribution outside California: to Alaska, ne US
Synonyms: P. p. (Aiton) A. Gray
Horticultural information: IRR or WET: 4, 5, 6, 15, 16, 17 &SHD: 7, 8, 9, 14, 19, 20, 21, 22, 23, 24; GRCVR (deciduous in winter); may be INV; also STBL.

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