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.

CHAENACTIS

PINCUSHION

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.

Native

C. stevioides Hook. & Arn.

DESERT PINCUSHION

Annual, branched above or below, sometimes ± scapose
Stems 1–many, erect, < 45 cm, cobwebby (at least thinly so near base); hairs thinning with age
Leaves < 11 cm, ± cobwebby, generally not fleshy; basal rosette generally withering; largest blades 1–2-pinnately lobed, lobes 4–8 pairs, crowded to well separated, longest near middle, tips generally curled
Inflorescence: heads generally several per stem; peduncles < 11 cm; involucre obconic to hemispheric, glandular-hairy or ± cobwebby; longest phyllaries 5.5–8(10) mm, tips erect, ± rigid, generally blunt
Flowers: corollas white to pink, rarely pale yellow, outer bilateral, greatly enlarged, inner radial, 4.5–6.5 mm
Fruit 4–6.5 mm; pappus scales 4–5 in 1(–2) series, scales of outer fruit < inner, unequal, scales of inner fruit equal to unequal, longest 1.5–6 mm
Chromosomes: 2n=10
Ecology: Common. Open flats, slopes
Elevation: < 2100 m.
Bioregional distribution: Inner South Coast Ranges, East of Sierra Nevada, Desert
Distribution outside California: to se Oregon, sw Idaho, w Colorado, sw New Mexico, nw Mexico
Flowering time: Spring
Synonyms: var. brachypappa (A. Gray) H.M. Hall; C. mexicana Stockw
Highly variable, but not clearly divisible. SCoRI plants resemble C. gillespiei Stockw. of c AZ (stem ± glabrous, leaf lobes elongate). See also C. carphoclinia
Horticultural information: TRY.