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Schoenoplectus americanus
OLNEY'S THREE-SQUARE BULRUSH


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(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


Common Name: NAKED-STEMMED BULRUSHES
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 americanus (Pers.) Volkart ex Schinz & R. Keller
NATIVE
Habit: Perennial herb 0.4--2.5 m; rhizome long, 2--5 mm diam. Stem: 3--10 mm diam, sides 3, deep-concave (flat), edges sharp. Leaf: blades 1--3, < 1.5 × sheath, 2--8 mm wide, 3-sided toward tip, +- flat; sheath not splitting. Inflorescence: head-like; inflorescence bract generally erect, 1--6 cm; spikelets 2--20, 5--15 mm, 3--5 mm wide; flower bract 3--4 mm, tip notch 0.1--0.4 mm, awn 0.2--0.6 mm, often sparse-scabrous. Flower: perianth bristles (2)5--6(7), <= fruit; stigmas 2--3. Fruit: 1.8--2.8 mm, 1.3--2 mm wide, 2- or obscure-3-sided, smooth. Chromosomes: 2n=78.
Ecology: Mineral-rich or brackish marshes, shores, fens, springs; Elevation: < 2200 m. Bioregional Distribution: KR, NCoRO, CaRH, GV, SnFrB, SW, GB, D; Distribution Outside California: to British Columbia, Nova Scotia, Florida; Mexico to South America. Flowering Time: Summer Note: Hybrids with Schoenoplectus pungens intermediate between parental species, forming persistent clones, rare in California.
Synonyms: Scirpus americanus Pers.; Scirpus olneyi A. Gray
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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Citation for this treatment: S. Galen Smith 2012, Schoenoplectus americanus, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=80328, accessed on April 16, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 16, 2024.

Schoenoplectus americanus
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©2015 Keir Morse
Schoenoplectus americanus
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©2019 Steve Matson
Schoenoplectus americanus
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©2015 Keir Morse
Schoenoplectus americanus
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©2019 Steve Matson
Schoenoplectus americanus
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©2013 Neal Kramer

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Geographic subdivisions for Schoenoplectus americanus:
KR, NCoRO, CaRH, GV, SnFrB, SW, GB, 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.
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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 (fruiting time in some monocot genera).