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Isolepis cernua

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.
Genus: IsolepisView DescriptionDichotomous Key

Habit: Annual, perennial herb, cespitose, rhizomed or not. Stem: simple, cylindric, <= 0.5 mm diam, not hollow. Leaf: basal, spiraled, 1--few; blade vestigial to >> sheath, <= 1 mm wide; ligule 0. Inflorescence: terminal, head-like, inflorescence bracts 1--2, 2--33 mm, leaf-like; spikelets 1--3(15), +- ovate, +- flat or not, many-flowered, 1--10 mm, 1--2 mm wide; flower bracts spiraled, each with 1 flower in axil, ovate, membranous, tip entire, generally short-awned. Flower: bisexual; perianth 0; stamens 1--3, anthers >= 0.6 mm; style 1, thread-like, base +- enlarged or not, stigmas 2--3. Fruit: +- wide-obovate, generally +- white to dark brown, minute-papillate, prominent-ridged lengthwise, or smooth, mucronate; tubercle 0.
Species In Genus: 69 species: temperate, subtropics, +- worldwide, especially Africa, Australia. Etymology: (Greek, isos, equal, similar, and lepis a flower bract)
eFlora Treatment Author: S. Galen Smith

Isolepis cernua (Vahl) Roem. & Schult.
Habit: Annual (perennial herb?) 4--40 cm. Leaf: 1. Inflorescence: inflorescence bracts 2--6(23) mm; flower bracts not clasping shed fruit, basal <= 2 mm, others 1.2--1.8 mm, awn < 0.1 mm. Flower: stigmas 2--3. Fruit: 0.8--1 mm, 0.5--0.7 mm wide, 2--3-sided, shallower than wide, sides convex or +- concave, fine-papillate or smooth. Chromosomes: 2n=30.
Ecology: Sandy, sometimes brackish sea shores, bluffs, sand dunes, creeks, marshes; Elevation: < 800 m. Bioregional Distribution: NCo, GV, CCo, SnFrB, SCo, SnBr/DMtns; Distribution Outside California: to British Columbia; Texas (naturalized); South America, Eurasia, Africa, Australia, New Zealand. Flowering Time: Late spring--winter
Synonyms: Scirpus cernuus Vahl; Scirpus cernuus subsp. californicus (Torr.) Thorne; Scirpus cernuus var. californicus (Torr.) Beetle
eFlora Treatment Author: S. Galen Smith
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botanical illustration including Isolepis cernua


Citation for this treatment: S. Galen Smith 2017. Isolepis cernua, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 21, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on October 21, 2017.

Isolepis cernua
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© 2012 Vernon Smith
Isolepis cernua
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© 2016 Neal Kramer
Isolepis cernua
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© 2016 Neal Kramer
Isolepis cernua
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© 2004 Steve Matson
Isolepis cernua
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© 2016 Neal Kramer
Isolepis cernua
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© 2007 Neal Kramer

More photos of Isolepis cernua in CalPhotos

Geographic subdivisions for Isolepis cernua:
NCo, GV, CCo, SnFrB, SCo, SnBr/DMtns;
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.