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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

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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.



David J. Keil and Charles E. Turner

Annual to perennial herb (sometimes short-lived, dying after flowering once)
Stem generally erect
Leaves: lower generally tapered or petioled, often wavy-margined, generally pinnately lobed, ± dentate, lobes and teeth spine-tipped, margin generally spiny-ciliate, glabrous to tomentose; upper generally sessile, ± reduced
Inflorescence: heads discoid, 1–many; involucre cylindric to spheric; phyllaries many, graduated in several series, outer spine-tipped; receptacle flat, long-bristly
Flowers generally many; corollas ± bilateral, white to red or purple, tube long, slender, lobes linear; anther bases sharply sagittate, tips oblong; style tip with slightly swollen node, appendage (above node) long, cylindric, branches very short
Fruit ovoid, glabrous; scar slightly angled; pappus bristles many, plumose, ± persistent or falling in ring
Species in genus: ± 200 species: North America, Eurasia
Etymology: (Greek: thistle)
Taxa difficult, incompletely differentiated, hybridize.


C. rhothophilum S.F. Blake


Biennial (or short-lived perennial herb) 1–10 dm, ± fleshy, bush-like or low, mounded, gray-tomentose throughout; hairs appressed, felt-like
Stem 1–several
Leaves generally very strongly wavy; lower 10–25 cm, wing-petioled, entire or ± widely lobed, lobes entire or few-toothed, main spines 1–4 mm; cauline gradually reduced, well-distributed, upper sessile, clasping, ± lobed, often spinier than lower, spines < 8 mm
Inflorescence: heads 1–several, ± clustered, closely subtended by uppermost leaves; peduncles 0–7 cm; involucres 3–4 cm, 4–6 cm diam, hemispheric or bell-shaped; phyllaries linear-lanceolate, persistently tomentose, outer and middle spiny-ciliate, spine tips 2–5 mm
Flowers: corollas 20–25 mm, white to pale yellow, tube 11–13 mm, throat 5–6 mm, lobes 5–8 mm; anthers brown
Fruit 5–7 mm, light-brown to black, thick or ± compressed; pappus 15–20 mm
Chromosomes: 2n=34
Ecology: Dunes, bluffs
Elevation: < 20 m.
Bioregional distribution: s Central Coast (s San Luis Obispo and n Santa Barbara cos.).
See the CNPS Inventory for information about endangerment and rarity.
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