| TREATMENT FROM THE JEPSON MANUAL (1993) |
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Jepson Interchange (more information) |
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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. |
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY |
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.
Annual, perennial herb, shrubs
Stems prostrate to erect
Leaves simple, opposite, sessile or petioled
Inflorescence: heads radiate or discoid, borne in stalked or sessile, open to very condensed, sometimes head-like cymes; peduncles 0 or slender; involucre ± cylindric; phyllaries 2–5
Ray flowers 0 or 1; corollas yellow or cream; ligules very small
Disk flowers 1–15; corollas yellow; style tips flattened, obtuse
Fruit 10-ribbed, ± flattened, glabrous, shining; pappus 0 (rarely of 2–4 scales)
Species in genus: 21 species: North America, South America, Australia
Etymology: (Latin: yellow)
| Introduced |
Annual, often rounded
Stems 15–80 cm
Leaves 3–15 cm, lanceolate, oblanceolate, elliptic or ovate, petioled or upper sessile; bases often fused around stem; tip acute to obtuse; margin dentate or serrate; surfaces glabrous
Inflorescence: heads in dense sessile, head-like clusters at forks of stem; involucres < 1 mm diam; phyllaries generally 2, 4–4.5 mm, oblong, obtuse
Ray flowers generally 1; ligule 0.5–1 mm, creamy yellow
Disk flowers: corollas 2–2.5 mm
Fruit 2–2.6 mm, black
Chromosomes: 2n=36
Ecology: Moist soil in waste places, cultivated areas
Elevation: < 200 m.
Bioregional distribution: e South Coast
Distribution outside California: native to Arizona to se US, S.America