ASTERACEAE

SUNFLOWER FAMILY

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.

HESPEREVAX

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.

Native

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.

Native

var. ambusticola J. Morefield

FIRE EVAX

Stems ± prostrate, < 5 cm
Leaves petioled; longest generally 4–7 mm, 1–2 mm wide, obtuse
Inflorescence: upper heads ± 2–2.5 mm, 1.5–2 mm wide; inner chaff scales 1.6–2 mm
Pistillate flowers in generally 2–3 series
Fruit generally 0.8–1 mm
Ecology: UNCOMMON. Bare, generally burned slopes
Elevation: 500–1300 m.
Bioregional distribution: s Inner North Coast Ranges, c-s Sierra Nevada Foothills, e San Francisco Bay Area, Outer South Coast Ranges, Peninsular Ranges.