Jepson Flora Project: Jepson Interchange    

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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 < 18 cm, ± green to gray-woolly
Leaves alternate or seeming whorled; base hard, yellowish; blade oblanceolate to ± round, entire
Inflorescence: heads disciform, sessile, 1–many above (sometimes scattered below), leafy-bracted, < 5 mm; phyllaries 0; receptacle conic, ± acuminate, short-shiny-bristly; chaff scales phyllary-like, subtending flowers, flat to concave, persistent, rigid, outer acute, ± glabrous, inner obtuse, finely woolly inside
Pistillate flowers in 1–5 series, cylindric
Disk flowers staminate, 2–6(12), ± bilateral, 3–5-lobed
Fruit obovoid, compressed front-to-back, ± angled, smooth, dull, ± black-banded near base; pappus 0
Species in genus: 3 species: CA, s OR
Etymology: (Greek: western Evax )
Reference: [Morefield 1992 Syst Bot 17:293–310]
Segregated from Evax ; closest to Ancistrocarphus. Evax multicaulis DC. and E. prolifera of AZ & NM not adequately documented from CA.


H. acaulis (Kellogg) Greene

Stem 0–8 cm
Leaves ± crowded near stem tips, longest 4–32 mm, < 5 mm wide; petiole < 1.5 X blade
Inflorescence: head generally 1, 2–4 mm, 1.5–3.5 mm wide, sometimes in dense groups of 2–8, groups < 8 mm wide, subtended by generally 6–12 leaves; lower heads 0 or < upper; receptacle < 2 X longer than wide; chaff in spiral ranks, inner scales 1.6–3.2 mm, tip exserted, spreading over outer scales
Pistillate flowers in 2–5 series
Disk flowers 0.6–1 mm
Fruit 0.6–1.6 mm
Ecology: Sandy slopes, flats, sometimes burns
Elevation: 100–1300 m.
Bioregional distribution: Northwestern California, Sierra Nevada Foothills, Great Central Valley, Central Western California, Peninsular Ranges
Distribution outside California: to sw Oregon
Synonyms: Evax a. (Kellogg) Greene (1883); E. a. Greene (1894) misapplied
Varieties intergrade.

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