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	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

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.

TETRADYMIA

COTTON-THORN, HORSEBRUSH

Shrubs
Stems ± tomentose
Leaves alternate and generally clustered in axils, linear to (ob)lanceolate, sometimes persisting as stiff spines, glabrous to tomentose
Inflorescence: heads discoid, axillary or in ± rounded, terminal clusters; involucre cylindric to hemispheric; phyllaries in 1–2 ± equal series, often keeled; receptacle naked
Disk flowers generally 4–8; corollas cream to yellow, lobes long, spreading; anther bases ± sagittate, tips obtuse or acute; style branches papillate to short-bristly, tips truncate to conic
Fruit obconic or fusiform, often angled; pappus 0 or of generally many bristles or slender scales
Species in genus: 10 species: w North America
Etymology: (Greek: 4 together, from 4-flowered heads of some)
Reference: [Strother 1974 Brittonia 26:177–202]
Esp flower buds TOXIC to sheep (toxicity poorly understood).

Native

T. glabrata Torr. & A. Gray

Plant < 12 dm, unarmed
Stems unevenly tomentose, becoming ± glabrous in stripes below nodes
Leaves: main leaves 5–10(20) mm, narrowly awl-shaped, ascending to appressed, sparsely woolly or becoming glabrous; clustered leaves 3–10(15) mm, thread- to ± club-like, glabrous
Inflorescence: heads generally 3–7; peduncles generally 5–10 mm, bracts 0; involucre 7–10 mm, obconic; phyllaries 4, lanceolate to obovate
Flowers 4; corollas 9–10 mm, cream to golden yellow
Fruit 3–5 mm, short-stiff-hairy; ribs glandular; pappus of many fine bristles, 6–8 mm
Chromosomes: 2n=60,62,120,180
Ecology: Sagebrush scrub, pinyon/juniper or Joshua-tree woodland
Elevation: 800–2400 m.
Bioregional distribution: Great Basin Floristic Province, Mojave Desert
Distribution outside California: to Oregon, Idaho, Utah
Flowering time: May–Jul
Horticultural information: TRY.