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Higher Taxonomy
Family: CyperaceaeView DescriptionDichotomous Key

Habit: Annual, perennial herb, often rhizomed or stoloned, often of wet open places; roots fibrous; monoecious, dioecious, or flowers bisexual. Stem: generally 3-sided, generally solid. Leaf: generally 3-ranked; base sheathing, sheath generally closed, ligule generally 0; blade (0 or) linear, parallel-veined. Inflorescence: spikelets generally arranged in head-, spike-, raceme-, or panicle-like inflorescences; flower generally sessile in axil of flower bract, enclosed in a sac-like structure (perigynium) or generally not. Flower: unisexual or bisexual, small, generally wind-pollinated; perianth 0 or generally bristle like; stamens generally 3, anthers attached at base, 4 chambered; ovary superior, chamber 1, ovule 1, style 2--3-branched. Fruit: achene, 2--3 sided.
Genera In Family: +- 100 genera, 5000 species: especially temperate. Note: Difficult; taxa differ in technical characters of inflorescence, fruit. In Carex and Kobresia, what appear to be individual pistillate flowers in fact are highly reduced inflorescences (whether or not the same applies to staminate flowers is still under debate). In some other works (e.g., FNANM) these are called spikelets, and they are treated as being arranged in spikes. Here and in TJM (1993), what appear to be individual pistillate flowers are called pistillate flowers in Carex (and they are treated as being arranged in spikelets), but spikelets in Kobresia (and they are treated as being arranged into spikes). Though internally inconsistent, the approach here is consistent with traditional usage, and reflects a preference for character states that may be determined in the field. Molecular, morphological, and embryological evidence indicates that Eriophorum crinigerum is to be segregated to a new genus, as Calliscirpus criniger (A. Gray) C.N. Gilmour et al., along with a second, newly described species, Calliscirpus brachythrix C.N. Gilmour et al. (Gilmour et al. 2013); key to genera modified by Peter W. Ball to include Calliscirpus.
eFlora Treatment Author: S. Galen Smith, except as noted
Scientific Editor: S. Galen Smith, Thomas J. Rosatti, Bruce G. Baldwin.

Habit: Perennial herb, cespitose to loosely cespitose to rhizomed with internodes > 1 cm; generally monoecious. Stem: generally sharp-3-angled, generally solid. Leaf: 3-ranked, generally glabrous except generally scabrous on midrib, margin; sheath closed, back (blade side of stem) green, ribbed, front (non-blade side of stem) generally thin, translucent, sometimes cross-wrinkled or flat, forming generally U-shaped mouth at top, sometimes extending above blade as a fragile sleeve-like "contraligule" (especially Groups 7, 11), sometimes disintegrating to a ladder- or lattice-like network or fringe of veins ("leaf sheath fronts fibrous"). Inflorescence: spikelets generally several to many, in spike, raceme, panicle, or head-like arrangement, each 1--many-flowered, generally unisexual, or bisexual, then staminate flowers distal to pistillate ("staminate/pistillate"), pistillate distal to staminate ("pistillate/staminate"), or otherwise, generally subtended by spikelet bract, lowest subtended by inflorescence bract, occasionally some additional pistillate spikelets on lateral shoots from basal nodes ("basal spikelets"); flowers subtended by flowering bract ("scale" in other literature, especially for pistillate). Flower: unisexual; perianth 0. Staminate Flower: stamens generally 3. Pistillate Flower: enclosed by sac-like structure (perigynium, abbreviated to "peri" here), occasionally next to bristle-like axis; style 1, stigmas 2--3(4), exserted. Fruit: 2--3(4)-sided, enclosed in peri, stalked or not, style base generally not persistent; peri body 2--3(4)-sided or round, often with marginal ribs, some with additional veins, papillate or not (determined at 20×), abruptly narrowed at base into stalk or not; peri beak abaxial flap (suture) prominent or generally inconspicuous or 0, tip open, often notched.
Species In Genus: +- 2000 species: worldwide; important components of peat, forage. Etymology: (Latin: cutter, from sharp leaf, stem edges) Note: Difficult because of many species, morphologic and genetic variation, minute key characters. Peri around fully mature fruit needed for identification (long-persistent peri often atypical). Many herbarium specimens have immature peri, which lead to misidentification. 2-styled plants with peri +- flat adaxially, curved abaxially are planoconvex; peri curved +- equally on both surfaces are biconvex. Peri walls said to be translucent are easily punctured and/or do not completely conceal fruit within. Peri beaks generally measured from point of inflection, where peri margin changes from convex to concave, to its tip, but in a few taxa it is measured from fruit top to beak tip ("measured from fruit top" for those taxa). Peri (and fruit) shapes including beak; peri (and fruit) "body" excludes beak. Mid to late season shoots often atypical in shape, color of inflorescence, bracts, peri. Number of peri given is per spikelet. Actual hybrids probably less frequent than reports of hybrids. Carex pityophila Mack, native to southern Rocky Mountains, reported from SnBr, but is distinct; plants from SnBr warrant a new species. In TJM (1993), Carex cephalophora Willd. misappl. to plants belonging instead to Carex mesochorea Mack. (Group 9), native to eastern United States, collected in SCo (Los Angeles Co.) in 1929 and in ScV (Butte Co.) in 2010. Carex molesta Mack. ex Bright (Groups 11A,G), native to eastern United States, an historical urban weed, Carex leavenworthii Dewey an urban weed. Carex cyrtostachya, Carex orestera, and Carex xerophila described since TJM2. Plants called Carex albonigra_in TJM2 are Carex orestera; Carex albonigra not in California.
Unabridged Note: Carex molesta Mack. ex Bright (Groups 11A,G), native to eastern United States, collected once from a parking space in SCo (Santa Barbara Co.) in 1958, making it an historical urban weed.
eFlora Treatment Author: Peter F. Zika, Andrew L. Hipp & Joy Mastrogiuseppe
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Citation for this treatment: Peter F. Zika, Andrew L. Hipp & Joy Mastrogiuseppe 2017. Carex, Revision 3, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 22, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on October 22, 2017.

Carex disperma
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© 2003 Steve Matson
Carex illota
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© 2003 Steve Matson
Carex leporinella
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© 2003 Steve Matson
Carex mariposana
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© 2007 Steve Matson
Carex serpenticola
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© 2016 Dana York
Carex vesicaria
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© 2006 Steve Matson

More photos of Carex in CalPhotos