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Vascular Plants of California
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Amphiscirpus nevadensis

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: AmphiscirpusView Description 


Species In Genus: 1 sp. Etymology: (Greek amphi-, doubtful, ambiguous, and Latin scirpus, bulrush)
eFlora Treatment Author: S. Galen Smith
Reference: Smith 2002 FNANM 23:27--28
Amphiscirpus nevadensis (S. Watson) Oteng-Yeb.
Habit: Perennial herb, 10--70 cm, smooth, tough, wiry; rhizomes long, 1--4 mm diam, tough, hard; stem, leaf air cavities 0. Stem: simple, 0.5--2 mm diam, +- cylindric, ridged. Leaf: basal, spiraled; sheath often disintegrating to fibers; ligule ciliate; blades 5--10, C-shaped in ×-section, distal > sheath, 0.5--2 mm wide, tip sharp, margin sparse-scabrous. Inflorescence: terminal, head-like, bracts leaf-like, main bract spreading or erect, 1--15 mm; spikelets 1--6(10), 5--20 mm, 3--5 mm wide, ovate to lanceolate, not +- flat, flowers many, 1 per flower bract; flower bracts spiraled, pale to dark red-brown, shiny, smooth, glabrous, papery to tough, hard, margins ciliate, basal 1--2 often like involucre, to 15 mm, with awn-like blade, others +- 4 mm, 3 mm wide, ovate, in proximal part of spikelet 3--9-veined, at least in distal-most 1-veined, tip not notched. Flower: bisexual; perianth of 1--6 barbed bristles; stamens 3, anthers +- 2 mm; style 1, thread-like, base not enlarged; stigmas 2. Fruit: 2-sided, 2--2.3 mm, 1.5--1.7 mm wide, obovate, brown, smooth, beak 0; tubercle 0.
Ecology: Saline, often alkaline seasonal wetlands; Elevation: 400--2400 m. Bioregional Distribution: CaR, GB, D; Distribution Outside California: southern South America. Flowering Time: Summer Note: Superficially like Schoenoplectus pungens.
Synonyms: Scirpus nevadensis S. Watson;
Jepson eFlora Author: S. Galen Smith
Reference: Smith 2002 FNANM 23:27--28
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Citation for this treatment: S. Galen Smith 2012, Amphiscirpus nevadensis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on December 16, 2018.

Citation for the whole project: Jepson Flora Project (eds.) 2018, Jepson eFlora,, accessed on December 16, 2018.

Amphiscirpus nevadensis
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© 2004 Steve Matson
Amphiscirpus nevadensis
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© 2004 Steve Matson
Amphiscirpus nevadensis
click for enlargement
© 2004 Steve Matson
Amphiscirpus nevadensis
click for enlargement
© 2004 Steve Matson
Amphiscirpus nevadensis
click for enlargement
© 2005 Steve Matson
Amphiscirpus nevadensis
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© 2014 Dylan Neubauer

More photos of Amphiscirpus nevadensis in CalPhotos

Geographic subdivisions for Amphiscirpus nevadensis:
CaR, GB, D;
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, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time.