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Schoenoplectus torreyi

(Torrey's Bulrush)

Interesting Facts

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Common Names

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Common Names in English:

Torrey's Bulrush, Torrey's Three-Square Bulrush

Common Names in French:

Scirpe De Torrey

Description

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Family Cyperaceae

Herbs, annual or perennial , cespitose or not, rhizomatous or not, stoloniferous or not. Roots fibrous , principally adventitious. Stems (culms ) usually trigonous , occasionally terete , rarely compressed , usually solid, rarely hollow or septate . Leaves basal and/or cauline, alternate, usually 3-ranked, rarely 2-ranked or multi-ranked, bases forming cylindric sheaths enclosing stem, margins usually fused; junction of sheaths and blades often with adaxial flaps of tissue or fringes of hair (ligules) ; blades frequently absent from some basal leaves , rarely from cauline leaves, when present divergent or ascending , flat, folded, plicate , rolled, or terete, linear , venation parallel. Primary inflorescences (spikelets ) a shortened axis; glumaceous bracts (scales ) 1-many, spirally arranged , sometimes 2-ranked, usually appressed or ascending; scales usually all fertile , each subtending a single flower, sometimes proximal and/or distal scales empty; lateral spikes often with basal, usually empty, usually 2-keeled scale (prophyll) ; occasionally prophyll subtending and enclosing rachilla, bearing 1 pistillate , sometimes (0-) 3 staminate flowers and empty scales (Carex, Cymophyllus, and Kobresia) . Secondary inflorescences panicles, often modified to corymb, pseudoumbel, cyme (anthela), raceme , spike, or capitulum (head ), rarely single spike, usually subtended by foliaceous or, less frequently, glumaceous bracts; secondary inflorescences sometimes simulating spikelets (Carex, Cymophyllus, and Kobresia) . Flowers hypogynous, bisexual in most genera, unisexual in Scleria, Carex, Cymophyllus, and Kobresia; perianth absent or with (1-) 3-6(-30) bristles and/or scales, usually falling off with fruit; stamens usually (1-) 3, rarely more, usually distinct ; anthers basifixed ; pistils 1, 2-3(-4) -carpellate, fused, locule 1; style undivided or branches 2-3(-4) ; stigma sometimes papillate . Fruits achenes, usually trigonous or biconvex ; pericarps thin (except in Scleria) . Seeds 1; testa thin, free from pericarp; embryo basal; endosperm abundant. x = 5-ca. 100.

Genera ca. 100, species ca. 5000 (27 genera, 843 species in the flora ) : worldwide.

No consensus exists regarding the number of genera and the overall relationships of genera within Cyperaceae. The most recent account of the family (P. Goetghebeur 1998) recognized 104 genera distributed among 4 subfamilies and 14 tribes . That arrangement differs somewhat from that of J. Bruhl (1995) . With one minor exception the arrangement of the family here follows that of Goetghebeur.

The family is characterized by the occurrence of a number of unusual cytological features including: (1) chromosomes with diffuse centromeres , (2) post-reductional meiosis, and (3) pollen grains formed from tetrads in which 3 of the 4 microspores fail to develop. The first two features are found in at least some Juncaceae and are unique to the two families. Juncaceae also have pollen in tetrads, but in that family all four microspores produce pollen grains. Some species in some genera of Cyperaceae (particularly Eleocharis) possess chromosomes with localized centromeres (S. S. Bir et al. 1993) . The wide range of chromosome numbers found in Cyperaceae is largely because of agmatoploidy; polyploidy has been hypothesized for some genera, especially Eleocharis, although polyploidy has not been demonstrated unequivocally.

Because of morphologic similarities in vegetative and inflorescence characters, the family has commonly been associated with Poaceae. Cytological features discussed above clearly indicate that to be a superficial similarity . Data from rbcL studies also support the view that Cyperaceae and Poaceae are not closely related (M. R. Duvall et al. 1993b; G. M. Plunkett et al. 1995) ; they do support the concept of close relationship between Cyperaceae and Juncaceae.

For most families of flowering plants the phenological data given are flowering times. Because most Cyperaceae cannot be reliably identified when in flower, in this volume fruiting time is given for all species by season , sometimes qualified by early, mid, or late, or by months. The fruiting time has been interpreted broadly to include the period when the fruit is more or less fully formed but not yet ripe . The fruiting period provided covers the entire range of the taxon . Quite a difference between fruiting periods in different parts of the range of the species may well occur, especially for widespread species and species with extensive elevation range.

For a recent, comprehensive review of the economic importance of Cyperaceae, see D. A. Simpson and C. A. Inglis (2001) .[1]

Genus Schoenoplectus

Herbs, perennial or annual , cespitose or not, rhizomatous or not. Culms solitary or not, cylindric to strongly trigonous , smooth , glabrous , spongy with internal air cavities. Leaves basal, rarely 1(2) cauline; sheaths tubular ; ligules membranous, glabrous; blades well developed to rudimentary , cross section dorsiventrally flat to C-shaped or laterally compressed , soft, smooth or margins sometimes distally scabrous or spinulose . Inflorescences terminal , capitate to openly paniculate ; spikelets 1100+; involucral bracts 15, leaflike, proximal bract erect to spreading . Spikelets terete , 325 × 25 mm; scales deciduous, 8+, spirally arranged , each subtending flower, or proximal scale empty (sometimes called a bracteole), floral scales with apex entire or 2-fid, midrib usually prolonged into mucro or awn , smooth or abaxial surface scabrous, margins ciliate . Flowers bisexual (basal flowers pistillate in amphicarpic species) ; perianth of 06(8) bristles , straight or curved , spinulose, straplike, sometimes fringed with soft, blunt hairs , shorter than to somewhat exceeding achene; stamens 3; anthers 3 mm; styles linear , 23-fid, base not or scarcely enlarged, deciduous in fruit. Achenes biconvex to trigonous, with apical beak , faintly to prominently rugose or with transverse wavy ridges , 2.53.5 mm including 0.12 mm beak.

Species ca. 77: worldwide.

Schoenoplectus includes some difficult species complexes, each with different ranges outside of North America, that are discussed under the first species in each complex . The four sections recognized here were delineated by S. G. Smith and E. Hayasaka (2001). About ten species from eastern Asia and Africa have not yet been assigned to a section.

Schoenoplectus californicus and members of the S. lacustris and S. pungens complexes are often ecologically dominant in wetlands, where they provide valuable food and habitat for waterfowl and other animals. In North America their culms are used, mostly historically, for making mats, baskets, chair seats, houses, boats , and other objects. Some species are cultivated as ornamentals . Indicator boxes for weediness are marked here on the basis of the status listed under Scripus.[2]

Physical Description

Species Schoenoplectus torreyi

Plants mat-forming; rhizomes 1-3 mm diam. Culms sharply trigonous , sides concave distally, 0.4-1.5 m × 1.5-5 mm. Leaves 4-7, nearly equaling culm; sheath fronts delicately pinnate-fibrillose; blades 3-6, erect , the distal mostly longer than sheath, 1-2 mm, wide, proximally thickly V-shaped central region trigonous-channeled to laterally flattened, apically asymmetically laterally flattened-trigonous; apex often markedly eccentric , glabrous , smooth or angles papillose . Inflorescences capitate or 1 spikelet ; proximal bract erect, resembling leaf blade, 3-20 cm. Spikelets 1-4, 7-18 × 3-5 mm; scales straw-colored to orange-brown or central region greenish, ovate-lanceolate, 4-5 × 2.5 mm, margins entire, smooth or awn sparsely spinulose , sometimes distally ciliolate at 40X, apex acute, mucronate , mucro 0.2-0.5 mm. Flowers: perianth members 6, brown, bristlelike, equaling to slightly exceeding achene, spinulose; anthers 2-3 mm; styles 3-fid. Achenes brown, compressed trigonous, ovoid to obovoid , 3.5-4.5 × 1.7-2 mm; beak 0.5-1 mm. 2n = 70. Fruiting summer. [source]

Schoenoplectus torreyi is very locally distributed, and probably has been extirpated from many historic localities. A specimen from an uncertain locality in Kentucky was collected in 1830. I have not seen specimens from North Dakota, South Dakota, or Nebraska. Scirpus torreyi was placed in synonymy under S. subterminalis Torrey var. cylindricus (Torrey) T. Koyama [misapplied, = Bolboschoenus novae-angliae by T. Koyama (1962b) ]. [source]

Habit: Graminoid

Habitat

Emergent in fresh ponds and marshes, often with fluctuating water levels; 10-200 m [3].

Typically found at an altitude of 0 to 678 meters (0 to 2,224 feet).[4]

Biology

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Reproduction

Duration: Perennial

Taxonomy

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Synonyms

Proc. Providence Franklin Soc. 1: 32. 1847 • Schoenoplectus lacustris creber (Fern.) A. & D. Löve • Schoenoplectus lacustris tabernaemontani (K. c. Gmel.) A. & D. Löve • Schoenoplectus lacustris validus (Vahl) T. koyama • Schoenoplectus validus (Vahl) A. & D. Löve • Schoenoplectus validus creber (Fern.) A. & D. Löve • Schoenoplectus validus luxurians (Miq.) Soják • Scirpus lacustris creber (Fern.) T. Koyama • Scirpus lacustris glaucus (Reichenb.) Hartman • Scirpus lacustris tabernaemontani (K. C. Gmel.) Syme • Scirpus lacustris validus (Vahl) T. Koyama • Scirpus tabernaemontani K. C. Gmel. • Scirpus torreyi Olney • Scirpus validus Vahl • Scirpus validus var. creber Fern.

Notes

Name Status: Accepted Name .

Last scrutiny: 21-Jun-2005

Similar Species

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Members of the genus Schoenoplectus

ZipcodeZoo has pages for 40 species, subspecies, varieties, forms, and cultivars in this genus:

S. acutus (Hardstem Bulrush) · S. acutus var. acutus (Hardstem Bulrush) · S. acutus var. occidentalis (Tule) · S. americanus (American Bulrush) · S. californicus (California Bulrush) · S. californicus var. spoliatus (California Bulrush) · S. californicus var. tereticulmis (California Bulrush) · S. carinatus (Oblong Bulrush) · S. contortus (Contorted Bulrush) · S. deltarum (Delta Bulrush) · S. erectus (Sharpscale Bulrush) · S. etuberculatus (Canby's Bulrush) · S. fluviatilis (River Bulrush) · S. glaucus (Tuberous Bulrush) · S. hallii (Hall's Bulrush) · S. heterochaetus (Pale Great Bulrush) · S. juncoides (Kaluha) · S. lacustris (Lakeshore Bulrush) · S. lacustris tabernaemontani 'Albescens' (Variegated Bulrush) · S. lacustris tabernaemontani 'Zebrinus' (Zebra Rush) · S. maritimus (Cosmopolitan Bulrush) · S. mucronatus (Bog Bulrush) · S. mucronatus f. hosoiri (Rough-Seed Bulrush) · S. novae-angliae (New England Bulrush) · S. pungens (Common Threesquare) · S. pungens var. badius (Common Threesquare) · S. pungens var. longebracteatus (Common Threesquare Bulrush) · S. pungens var. longispicatus (Common Threesquare) · S. pungens var. polyphyllus (Common Threesquare Bulrush) · S. pungens var. pungens (Common Threesquare) · S. purshianus (Weakstalk Bulrush) · S. robustus (Sturdy Bulrush) · S. saximontanus (Rocky Mountain Bulrush) · S. smithii (Smith's Bulrush) · S. subterminalis (Swaying Bulrush) · S. tabernaemontani (Bullrush) · S. torreyi (Torrey's Bulrush) · S. triqueter (Streambank Bulrush) · S. triqueter f. hoppei (Triangular Club-Rush) · S. x carinatus (Oblong Bulrush)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal November 22, 2007:

Identifiers

Footnotes

  1. Peter W. Ball, A. A. Reznicek, David F. Murray "Cyperaceae". in Flora of North America Vol. 23 Page 3, 4, 192, 243, 252. Oxford University Press. Online at EFloras.org. [back]
  2. S. Galen Smith "Schoenoplectus". in Flora of North America Vol. 23 Page 6, 7, 8, 28, 38, 44, 48, 168. Oxford University Press. Online at EFloras.org. [back]
  3. "Schoenoplectus". in Flora of North America Vol. 23 Page 46, 51, 54. Oxford University Press. Online at EFloras.org. [back]
  4. Mean = 265.610 meters (871.424 feet), Standard Deviation = 168.080 based on 106 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
Last Revised: 7/15/2012