Jepson eFlora: Taxon page
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon
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-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.
Species In Genus: +- 77 species: temperate, subtropics, worldwide. Etymology: (Greek, schoenos, a rush, reed, and plectos, plaited, twisted, woven, in reference to the use of stems in making useful objects)

Schoenoplectus americanus (Pers.) 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
Unabridged Note: Expanded author citation: Schoenoplectus americanus (Pers.) Volkart ex Schinz & R. Keller
eFlora Treatment Author: S. Galen Smith
Jepson Online Interchange

Previous taxon: Schoenoplectus acutus var. occidentalis
Next taxon: Schoenoplectus californicus

Name Search

Contact/Feedback

Citation for this treatment: S. Galen Smith 2016. Schoenoplectus americanus, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=80328, accessed on February 12, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on February 12, 2016.


Schoenoplectus americanus
click for enlargement
© 2015 Keir Morse
Schoenoplectus americanus
click for enlargement
© 2010 Neal Kramer
Schoenoplectus americanus
click for enlargement
© 2010 Neal Kramer
Schoenoplectus americanus
click for enlargement
© 2015 Keir Morse
Schoenoplectus americanus
click for enlargement
© 2013 Neal Kramer
Schoenoplectus americanus
click for enlargement
© 2010 Neal Kramer

More photos of Schoenoplectus americanus in CalPhotos


Geographic subdivisions for Schoenoplectus americanus:
KR, NCoRO, CaRH, GV, SnFrB, SW, GB, D;
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS
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).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

CCH collections by month

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