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Scirpus diffusus

Higher Taxonomy
Family: CyperaceaeView DescriptionDichotomous Key

Common Name: SEDGE FAMILY
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: ScirpusView DescriptionDichotomous Key

Common Name: BULRUSH
Habit: Perennial herb, rhizomed [not], glabrous; roots fibrous. Stem: generally erect, 3-angled or cylindric, solid. Leaf: basal and cauline, 3-ranked; blades 4--11 per stem, linear, generally > sheaths, flat [V-shaped in ×-section], margins, generally midribs scabrous; sheaths not fibrous; ligule present or 0. Inflorescence: terminal or in axils of 1--3 distal leaves, spikelets 1 or few to many in panicle or head-like clusters; inflorescence bracts generally 3, leaf-like; spikelets < 5 mm diam; flower bracts 10--50, spiraled, 1--3.5 mm, sharp-pointed, each with 1 flower in axil. Flower: bisexual; perianth of (0)3--6 bristles, < or >> fruit, straight or strong-curled, smooth to barbed or toothed, generally persistent on fruit; stamens 1--3; style 2--3-branched, base persistent. Fruit: 0.5--1.8 mm, ovate, obovate, or elliptic, 2--3-sided, minute-papillate or -pitted.
Species In Genus: +- 35 species: North America, Mexico, Eurasia, Australia. Note: Other taxa in TJM (1993) moved to Amphiscirpus, Bolboschoenus, Isolepis, Schoenoplectus, Trichophorum.

Scirpus diffusus Schuyler
NATIVE
Habit: Spreading, +- 70--80 cm; rhizome long. Stem: 2--5 mm diam at middle, 3-angled. Leaf: ligule 0; blade 5--8 mm wide. Inflorescence: spikelets in head-like clusters, 3--6 mm, 1.5--2.5 mm wide; flower bract 1.4--2.6 mm, green to brown or +- black. Flower: perianth bristles < to > fruit, not exceeding flower bracts, +- curled to straight, teeth above middle, fine, generally reflexed. Fruit: 0.9--1.3 mm, 3-angled.
Ecology: Meadows, marshes, streambanks; Elevation: 200--2400 m. Bioregional Distribution: KR, s CaR, SN. Flowering Time: Jul
Unabridged Note: Geog pending study of additional specimens.
eFlora Treatment Author: S. Galen Smith
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Citation for this treatment: S. Galen Smith 2016. Scirpus diffusus, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=43686, accessed on August 23, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on August 23, 2016.


Scirpus diffusus
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© 2004 Steve Matson
Scirpus diffusus
click for enlargement
© 2004 Steve Matson
Scirpus diffusus
click for enlargement
© 2004 Steve Matson
Scirpus diffusus
click for enlargement
© 2004 Steve Matson
Scirpus diffusus
click for enlargement
© 2004 Steve Matson
Scirpus diffusus
click for enlargement
© 2004 Steve Matson

More photos of Scirpus diffusus in CalPhotos


Geographic subdivisions for Scirpus diffusus:
KR, s CaR, SN.
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.
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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.