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

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



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. hydrophilum (Greene) Jeps.

Biennial (or short-lived perennial herb) 1–2.1 m
Stem ± cobwebby, becoming glabrous
Leaves thinly cobwebby-tomentose (both surfaces) or becoming glabrous above; lower 3–9 dm, petiole spine-margined, blade generally ± lobed, lobes generally with 2–4(6) wide 2° lobes or coarse teeth, main spines 2–9 mm; middle and upper smaller, clasping or short-decurrent with ear-like bases, uppermost much reduced, generally very spiny, lobes narrower
Inflorescence: heads solitary or in small groups in ± open cymes or panicle-like clusters; peduncles 0–6 cm; involucres 1.5–2.5 cm, 1.5–3 cm diam, ovoid to bell-shaped, thinly cobwebby, becoming glabrous; outer and middle ovate to ovate-lanceolate, minutely spiny-ciliate, appressed, midribs with narrow sticky glandular area, spines 1–3 mm, spreading, inner linear-lanceolate or oblong, tips flat, ± twisted
Flowers: corollas 18–23 mm, pale rose-purple, tube 8–10 mm, throat 5–6 mm, lobes 5–7 mm
Fruit 4–5 mm, dark brown to black, ± thick; pappus ± 15 mm
Ecology: Wet soils
Elevation: < 450 m.
Bioregional distribution: Deltaic Great Central Valley, n San Francisco Bay Area. Related to C. douglasii and C. mohavense.

previous taxon | next taxon
bioregional map for CIRSIUM%20hydrophilum being generated

Retrieve Jepson Interchange Index to Plant Names entry for Cirsium hydrophilum
Retrieve dichotomous key for Cirsium
Retrieve multiple-entry key (MEKA) for Cirsium
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

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