TREATMENT FROM THE JEPSON MANUAL (1993) |
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©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora. |
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Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1many 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)45; stamens 45, 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):128. See glossary p. 25 for illustrations of general family characteristics.
Annual, perennial herb
Stems spreading to erect
Leaves generally pinnately divided or compound, alternate or opposite, sessile or petioled, gland-dotted
Inflorescence: heads radiate or discoid, solitary to many in cymes or secondary heads; peduncle 0 to long; bracts 0few, scattered; involucre widely obconic to hemispheric; phyllaries in 23 series, free, outer (when present) linear, inner wider, overlapping; receptacle flat to convex, naked
Ray flowers (0)58; corollas yellow to orange
Disk flowers generally many; corollas yellow to orange; style tips truncate to conic
Fruit obconic or obpyramidal; pappus of scales dissected into bristles
Species in genus: 4 species: North America., South America
Etymology: (Greek: disagreeable odor)
Reference: [Strother 1986 Sida 11:371378]
Introduced |
Annual generally 14 dm, glabrous or sparsely puberulent
Leaves opposite below, often alternate above, 23 cm, divided into 1115 narrow lobes, these sometimes again divided
Inflorescence: heads radiate, 1few in dense cymes; peduncles 15 mm; involucre 410 mm diam, bell-shaped; outer phyllaries 49, linear, inner phyllaries generally 8, scarious-margined, gland-dotted
Ray flowers 8 or fewer; ligules 1.52 mm
Disk flowers 2530; corollas ± 3 mm, pale yellow
Fruit 33.5 mm, hairy; pappus 23 mm
Chromosomes: 2n=26
Ecology: Roadsides, disturbed fields
Elevation: < 350 m.
Bioregional distribution: eastern South Coast (sw San Bernardino Co.)
Distribution outside California: widespread weed in America; native to c&eastern N.America, Mexico; also in w S.America