TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©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.

HYMENOXYS

Annual, biennial, perennial herb
Stems erect, simple to much-branched
Leaves simple, basal or alternate, sessile or petioled, entire or divided 1 or more times into linear lobes, dotted with sunken resin glands
Inflorescence: heads generally radiate, solitary or in few–many-headed cymes; involucre hemispheric; phyllaries in 2–3 similar or dissimilar series; receptacle flat to rounded, naked
Ray flowers few–many; corolla yellow, fan-shaped, 3–5-lobed
Disk flowers many; corolla yellow
Fruit obpyramidal, generally 5-angled, hairy; pappus of ± 5 membranous, often awn-tipped scales
Species in genus: 28 species: w North America, South America
Etymology: (Greek: sharp membrane, from pappus)
Horticultural information: TRY.

Native

H. odorata DC.

Annual 15–60 cm, soft-hairy, ± glabrous in age
Stems branched above
Leaves: basal generally 0 at time of flower; cauline 1–5 cm, divided into linear lobes 1 mm or less wide
Inflorescence: heads in flat-topped cyme; peduncles 2–15 cm; involucre generally 5–7 mm diam; outer phyllaries 3–5 mm, < inner phyllaries, thickened and fused at base
Ray flowers ± 8; ligules generally 1 cm or less, yellow, fading to cream and ± persistent on fruit
Disk flowers: corolla 3–4 mm
Fruit ± 2 mm; pappus scales 2 mm, lanceolate
Chromosomes: 2n=11,12,14,15
Ecology: Sandy flats near Colorado River
Elevation: < 150 m.
Bioregional distribution: e Sonoran Desert
Distribution outside California: to Utah, Texas, n Mexico
Flowering time: Feb–May
TOXIC range plant outside CA.