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Vascular Plants of California
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Schoenoplectus acutus var. occidentalis

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(4)-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: SchoenoplectusView DescriptionDichotomous Key

Habit: Generally perennial herb, generally erect, generally with long, scaly rhizomes; stem, leaf generally with air cavities. Stem: simple, smooth, (wiry). Leaf: generally all basal, whorled or 3-ranked; blade generally present, at least on distal sheath, smooth, or margin minute-scabrous; sheath closed, long; ligule glabrous. Inflorescence: terminal, branch stems often scabrous, main inflorescence bract like leaf blade; spikelets ovate, not +- flat, many-flowered; flower bracts spiraled, each with 1 flower in axil, ovate, 1-veined, brown to straw, dull, often fine-lined-spotted, membranous, generally +- scabrous, tip generally notched, generally with short awn. Flower: bisexual; perianth bristles +- straight, +- <= fruit, generally brown, reflexed-barbed (or with soft hairs) [(smooth)]; stamens generally 3; style 1, thread-like, base not enlarged, stigmas 2--3. Fruit: generally obovate, brown, generally smooth, mucronate; tubercle 0.
Etymology: (Greek, schoenos, a rush, reed, and plectos, plaited, twisted, woven, in reference to the use of stems in making useful objects)
eFlora Treatment Author: S. Galen Smith
Reference: Smith 2002 FNANM 23:44--60
Schoenoplectus acutus (Muhl. ex Bigelow) Á. Löve & D. Löve var. occidentalis (S. Watson) S.G. Sm.
Habit: Perennial herb 1--4 m; rhizome long, 5--15 mm diam. Stem: 2--10 mm diam, cylindric; wider air cavities in distal 1/4 +- 1--2.5 mm wide. Leaf: blades 1--2, << sheath, 3--7 mm wide; sheath splitting, leaving fibers. Inflorescence: panicle-like; inflorescence bract erect or spreading, 1--9 cm; spikelets 3--100+, in clusters of 1--8, not all 1 on 1 pl, 6--18 mm, 3--4 mm wide; flower bract 3--4 mm, 2--3 mm wide, sparse- (to dense-) scabrous, woolly-ciliate, often deciduously, tip notch 0.3--0.5 mm, awn 0.5--2 mm, often broken off, some or all markedly contorted. Flower: perianth bristles (4)6(8), (vestigial or) <= fruit; stigmas 2--3. Fruit: 2--3 mm, 1.2--1.7 mm wide, smooth, 2--3-sided.
Ecology: Common. Marshes, shores, fens, shallow lakes, often emergent; Elevation: < 2500 m. Bioregional Distribution: CA (exc e D); Distribution Outside California: to British Columbia, Montana, Texas. Flowering Time: Summer Note: Plants with stigmas 2, fruit 2-sided (Schoenoplectus acutus var. acutus) in eastern North America western to Alaska, Washington, Idaho, Texas, possible waif in California. Plants in southern California with stigmas generally 3, fruit generally 3-sided may deserve recognition as var. Intermediates to, putative hybrids with Schoenoplectus californicus collected in CCo, SnFrB, deltaic GV; putative hybrids with Schoenoplectus heterochaetus locally common, with Schoenoplectus tabernaemontani locally common in eastern North America.
Synonyms: Scirpus acutus Muhl. ex Bigelow var. occidentalis (S. Watson) Beetle
Unabridged Note: Occurrence of Schoenoplectus acutus var. acutus in California unresolved because it seems to intergrade completely with Schoenoplectus acutus var. occidentalis and diagnostic characters are difficult to determine.
Jepson eFlora Author: S. Galen Smith
Reference: Smith 2002 FNANM 23:44--60
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Schoenoplectus acutus var. occidentalis

botanical illustration including Schoenoplectus acutus var. occidentalis

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Citation for this treatment: S. Galen Smith 2012, Schoenoplectus acutus var. occidentalis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on April 20, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on April 20, 2024.

Schoenoplectus acutus  
var. occidentalis
click for enlargement
©2013 Neal Kramer
Schoenoplectus acutus  
var. occidentalis
click for enlargement
©2013 Neal Kramer
Schoenoplectus acutus  
var. occidentalis
click for enlargement
©2020 Neal Kramer
Schoenoplectus acutus  
var. occidentalis
click for enlargement
©2019 Steve Matson
Schoenoplectus acutus  
var. occidentalis
click for enlargement
©2019 Steve Matson

More photos of Schoenoplectus acutus var. occidentalis
in CalPhotos

Geographic subdivisions for Schoenoplectus acutus var. occidentalis:
CA (exc e D)
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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).


Data provided by the participants of the  Consortium of California Herbaria.
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All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

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 (fruiting time in some monocot genera).