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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.



James D. Morefield

Annual to subshrubs, generally ± hairy
Leaves alternate or basal, generally petioled, reduced upward, entire and linear or generally elliptic to ovate or obovate and 1–4-pinnately lobed; 1° lobes longest near middle or base of blade
Inflorescence: heads discoid (but outer flowers often enlarged, ± ray-like), 1–many per stem, generally in terminal cymes; peduncle generally hairy like phyllary bases; involucre generally < 15 mm diam, cylindric to obconic or hemispheric; phyllaries in 1–2 ± equal series, generally linear to lanceolate, tips generally ± flat, generally ± green; receptacle flat to rounded, generally naked
Flowers 10–many; 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 4–20 fringed scales in 1–few 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 67:1304–1309]
Spp. of sect. Chaenactis hybridize.


C. glabriuscula DC.


Stems generally 1–few, erect to spreading, < 50 cm; hairs thinning with age
Leaves < 11 cm, ± cobwebby, fleshy or not; largest entire or 1–2-pinnately lobed, 1° lobes 1–7 pairs, longest near blade middle, tips flat to curled or cylindric
Inflorescence: heads 1–several per stem; peduncle < 20 cm; involucre widely cylindric to obconic or hemispheric, generally ± tomentose or glandular-hairy; longest phyllaries 4.5–9 mm, tips erect, ± rigid, generally blunt
Flowers: corollas ± bright to deep yellow, outer bilateral, greatly enlarged, inner radial, 4–8 mm
Fruit 3–9 mm; pappus scales (1)4–8 in 1–2 series, scales of outer fruit generally < inner, unequal, scales of inner fruit generally equal, longest 1–8 mm
Chromosomes: 2n=12
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.


var. megacephala A. Gray

Plants branched generally below middle, generally becoming glabrous
Stems < 50 cm, ± erect
Leaves < 9 cm, generally not fleshy; basal rosette withering; largest blades generally 1-pinnately lobed, lobes 2–7 pairs, ± well separated, tips flat
Inflorescence: heads 1–few per stem; peduncles < 20 cm; involucre widely cylindric to hemispheric; longest phyllaries 7–9 mm, 2–3 mm wide, green, ± glabrous
Flowers: inner corollas 5–8 mm
Fruit 5–8.5 mm; pappus scales 4–5 in 1 series, longest 5–8 mm
Ecology: Dry, often sandy slopes
Elevation: < 1600 m.
Bioregional distribution: s Sierra Nevada Foothills, Tehachapi Mountain Area, San Joaquin Valley, Central Western California, n Southwestern California.± intermediate between vars. glabriuscula & heterocarpha
Horticultural information: TRY.

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bioregional map for CHAENACTIS%20glabriuscula%20var.%20megacephala being generated

Retrieve Jepson Interchange Index to Plant Names entry for Chaenactis glabriuscula var. megacephala
Retrieve dichotomous key for Chaenactis
Retrieve multiple-entry key (MEKA) for Chaenactis
Overlay Consortium of California Herbaria specimen data by county on this map
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