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This page is based on the 1993 Jepson Manual.
Please see the Jepson eFlora for up-to-date information about California vascular plants. |
| Jepson Flora Project: Jepson Interchange |
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TREATMENT FROM THE JEPSON MANUAL |
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Jepson Interchange (more information) |
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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 |
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 to subshrubs, generally ± hairy
Leaves alternate or basal, generally petioled, reduced upward, entire and linear or generally elliptic to ovate or obovate and 14-pinnately lobed; 1° lobes longest near middle or base of blade
Inflorescence: heads discoid (but outer flowers often enlarged, ± ray-like), 1many per stem, generally in terminal cymes; peduncle generally hairy like phyllary bases; involucre generally < 15 mm diam, cylindric to obconic or hemispheric; phyllaries in 12 ± equal series, generally linear to lanceolate, tips generally ± flat, generally ± green; receptacle flat to rounded, generally naked
Flowers 10many; corollas radial (outer, if enlarged, ± bilateral), generally white to pinkish or yellow, generally opening in daytime; anthers generally exserted
Fruit club-shaped, generally not compressed, stiffly hairy; pappus 0 or of 420 fringed scales in 1few series
Species in genus: 18 species: w North America
Etymology: (Greek: gaping ray, from enlarged outer corollas of some)
Reference: [Mooring 1980 Amer J Bot 67:13041309]
Spp. of sect. Chaenactis hybridize.
| Native |
Annual, branched below middle
Stems 1few, erect, < 35 cm, thinly tomentose; hairs thinning with age
Leaves < 6 cm, not fleshy; basal rosette withering; largest blades 1-pinnately lobed, lobes generally 25 pairs, ± well separated, longest near middle to ± near base, tips flat
Inflorescence: heads 1few per stem; peduncles < 9 cm; involucre widely cylindric, ± tomentose, glands 0; longest phyllaries 1218 mm, tips generally recurved, soft, blunt
Flowers: corollas all radial, 911 mm, ± equal, white to pinkish, generally opening at night; anthers ± included
Fruit 56 mm; pappus scales 8 in 2 series, longest 57 mm, outer << inner
Chromosomes: 2n=12
Ecology: Open (often calcareous) sand or gravel
Elevation: 10002000 m.
Bioregional distribution: Great Basin Floristic Province, n Mojave Desert
Distribution outside California: to se Oregon, sw Idaho, w Utah, n Arizona
Flowering time: Spring
| YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps). |
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