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.

TRIXIS

Shrubs
Leaves simple, alternate, sessile or petioled; blade long, entire or toothed, generally ± glandular
Inflorescence: heads discoid (but often appearing radiate), sessile or short-peduncled, in flat-topped or panicle-like cymes; involucre cylindric; phyllaries generally in 1 series, linear, keeled; receptacle flat, short-hairy
Flowers few–many; corolla yellow, 2-lipped, outer lip spreading, ligule-like, 3-lobed, sometimes recurved, inner lip 2-lobed, recurved or coiled; anthers exserted, base with tail-like appendages, tip oblong, acute; style tips truncate
Fruit ± cylindric, 5-ribbed, black or brown, short-hairy and glandular; pappus of many bristles
Species in genus: ± 65 species: North America, South America
Etymology: (Greek: 3-fold, from outer corolla lip)
Reference: [Anderson 1972 Mem NY Bot Gard 22(3):1–68]

Native

T. californica Kellogg var. californica

Plant glandular and short-hairy
Stems 2–20 dm, erect, stiff, much-branched
Leaves many; petiole 1.5–5 mm, winged; blade 2–11 cm, linear-lanceolate to lanceolate, acute at both ends, entire or serrate, margin often rolled under
Inflorescence: peduncles generally < or = 5 mm, bearing 5–7 bracts; phyllaries 8–10, 8–14 mm, green, tips acute
Flowers 11–25; corolla glandular, tube 6–9 mm, outer lip 5–8 mm, spreading, inner lip 4–5.5 mm, generally coiled
Fruit 6–10.5 mm; pappus 7.5–12 mm, dull white
Chromosomes: 2n=54
Ecology: Dry, rocky slopes, washes, desert flats
Elevation: generally < 1000 m.
Bioregional distribution: Desert
Distribution outside California: to Texas, n Mexico
Horticultural information: DRN, DRY, SUN: 10, 11, 12, 13, 19, 20, 21, 22, 23, 24.