Jepson Flora Project: Jepson Interchange    

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

CIRSIUM

THISTLE

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.

Native

C. brevistylum Cronquist

INDIAN THISTLE

Annual to biennial (or short-lived perennial herb) 3–20 dm
Stem generally 1, generally branched above middle, ± hairy with jointed hairs, often cobwebby below heads
Leaves sparsely hairy (hairs jointed) above, gray-tomentose below, sometimes becoming ± glabrous; lower 15–25 cm, tapered to spiny-winged petioles, generally shallowly lobed and dentate, main spines 3–7 mm; cauline gradually reduced, sometimes ± clasping or short-decurrent
Inflorescence: heads 1–several at stem tips, sometimes also in upper axils, ± sessile, closely subtended by bract-like leaves; involucres 2.5–3.5 cm, 2.5–4 cm diam, hemispheric to ± bell-shaped, loosely cobwebby; phyllaries in ± 5 series, linear, not strongly graduated, outermost sometimes spiny-ciliate near base, tip spines 3–5 mm, inner with tips straight, flat
Flowers: corollas 20–24 mm, white to purple, tube 10–14 mm, throat 4–5 mm, lobes 3–5 mm
Fruit 3–4 mm, ± brown; pappus 10–20 mm
Chromosomes: 2n=34
Ecology: Moist places
Elevation: < 500 m.
Bioregional distribution: North Coast, Outer North Coast Ranges, Central Coast, San Francisco Bay Area, South Coast
Distribution outside California: to Washington, British Columbia

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bioregional map for CIRSIUM%20brevistylum being generated
 
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Retrieve Jepson Interchange Index to Plant Names entry for Cirsium brevistylum
Retrieve dichotomous key for Cirsium
Retrieve multiple-entry key (MEKA) for Cirsium
Overlay Consortium of California Herbaria specimen data by county on this map
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