Jepson Flora Project: Jepson Interchange    

 
link to manual TREATMENT FROM THE JEPSON MANUAL (1993) previous taxon | next taxon
Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

    THIS PAGE IS NO LONGER UPDATED
    AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

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. comosa A. Gray

Plant 3–12 dm, ± spiny or not
Stems tomentose
Leaves: main leaves 2–6 cm, generally narrowly lanceolate, becoming rigid, spine-tipped but finally deciduous, tomentose; clustered leaves generally 0 (8–15 mm, ± oblanceolate)
Inflorescence: heads generally 3–6; peduncles generally 3–8 mm, tomentose, bract generally 1, narrow; involucre ± 8 mm, ± widely bell-shaped; phyllaries 5(6), elliptic to (ob)ovate, often unequal
Flowers 5–9; corollas 8–9 mm, (brownish) yellow
Fruit ± 4 mm; hairs long, white, pappus-like; pappus 0
Chromosomes: 2n=60
Ecology: Coastal scrub, chaparral, sagebrush scrub
Elevation: 300–1500 m.
Bioregional distribution: Transverse Ranges, Peninsular Ranges
Distribution outside California: n Baja California

previous taxon | next taxon
bioregional map for TETRADYMIA%20comosa being generated
 


Retrieve Jepson Interchange Index to Plant Names entry for Tetradymia comosa
Retrieve dichotomous key for Tetradymia
Retrieve multiple-entry key (MEKA) for Tetradymia
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
Return to the Jepson Interchange main page
Return to treatment index page
Glossary


University & Jepson Herbaria Home Page |
General Information | University Herbarium | Jepson Herbarium |
Visiting the Herbaria | On-line Resources | Research |
Education | Related Sites
Copyright © by the Regents of the University of California