Scirpus microcarpus

Taxonomy

Unambiguous Synonyms:

1. Scirpus microcarpus var. longispicatus M.E. Peck
2. Scirpus microcarpus var. rubrotinctus (Fern.) M.E. Jones
3. Scirpus rubrotinctus Fern.

Notes:

Name Status: Accepted Name. Latest taxonomic scrutiny: 15-Mar-2000

Physical Description

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 Scirpus:

Herbs, perennial, cespitose or not, rhizomatous or not. Culms solitary or not, ± trigonous. Leaves basal and cauline or all cauline; sheaths not fibrous; ligules present, rarely absent; blades flat or V-shaped in cross section, prominently keeled abaxially. Inflorescences terminal, sometimes also axillary in 1-3 distal leaves, subumbellate or corymbose-paniculate; spikelets 50-500; involucral bracts usually 3, leaflike. Spikelets less than 3.5(-5) mm diam.; scales 10-50, spirally arranged, each scale subtending flower, glabrous. Flowers bisexual; perianth of (0-) 3-6 bristles; bristles straight or strongly curled, smooth, or variously toothed, or barbed, shorter to much longer than achene, not obscuring scales in fruit; stamens 1-3; styles (2-) 3-fid, linear, base persistent. Achenes trigonous, biconvex or plano-convex, 0.6-1.8 mm, minutely papillose. x = 14.

Species ca. 35: North America, Mexico, Eurasia, Australia, Pacific Islands.

Culms are unbranched proximal to the inflorescence and reach 30-200 cm. Leaves range from 3 to 22(-26) per culm and are 3-ranked; blades are always well developed, 110-800 × 3-23 mm, smooth or with scabrous margins and midribs.

The inflorescence in Scirpus is a large compound cyme of 50-500 spikelets per inflorescence. The spikelets in the individual cymules may be sessile, with the cymules forming dense glomerules of spikelets, or the lateral (never terminal!) spikelets may be pedicellate, with the inflorescence larger and more open. Involucral bracts are spreading or ascending, 13-230 mm, or exceeding spikelets, smooth or margins and midrib scabrous.

Scales are deciduous, green, brown, or blackish, not keeled, without lateral ribs, uniform in length along spikelet, and the apex rounded to obtuse, mucronate, or short-awned.

When present the perianth is usually persistent, rarely caducous, white or brown; bristles are vestigial or to 8 mm, shorter to much longer than the scale; margins are smooth or antrorsely or retrorsely toothed or barbed. The filaments often persist after the anthers have been shed, and they are sometimes mistaken for perianth bristles. Only three filaments occur per flower; they are thicker than the bristles, do not taper distally like the bristles, and, unlike bristles in some species, are neither toothed nor contorted. The perigynium is absent.

Scirpus hybrids are usually sterile, or at least show greatly reduced fertility. Interspecific hybrids are usually easy to recognize because most or all of their ovaries are empty. In addition, their spikelets are often more elongate than the spikelets of the parent species; this is probably a result of low seed sets, because growth of the spikelet is not halted as nutrition is diverted to developing seeds.

Some species of Scirpus are weedy, and their small achenes are well adapted for accidental transport by humans. Most of the disjunct, outlying populations in species such as Scirpus pendulus and S. pallidus probably represent human introductions.^[2]

Habit: Graminoid

Flowers: Bloom Period: April, May. • Flower Color: near white, white

Distribution

Range and Population

North America

Native: .

Reproduction

Duration: Perennial

Similar Species

Members of the genus Scirpus:

There are approximately 998 species, subspecies, varieties, forms, and cultivars in this genus. Here are just 100 of them: S. americanus monophyllus · S. atrovirens pallidus · S. erectus raynalii · S. littoralis subulatus · S. microcarpus rubrotinctus · S. sylvaticus orientalis · S. aberrans · S. ablepharis · S. ablepharus · S. abnormalis · S. acaulis · S. acicularis · S. acicularis f. fluitans · S. acicularis f. submersus · S. acicularis var. rigidula · S. acicularis var. sc. filiformis · S. acicularis var. submersus · S. aciformis · S. acrostachys · S. acuminatus · S. acuta · S. acutangulus · S. acutus f. congestus · S. adscendens · S. aegyptiacus · S. aemulans · S. affinis · S. albescens · S. albibracteatus · S. albovittatus · S. albus · S. alpinus · S. altissimus · S. ambiguus · S. amentaceus · S. americanus f. cordilleranus · S. americanus var. longisetis · S. americanus var. triangularis · S. amphibius · S. analecta · S. analecti · S. anceps · S. ancistrochaetus (Barbed Bristle Bulrush) · S. angolensis · S. angolensis var. briziformis · S. angulatus · S. angustifolius · S. angustisquamis · S. anisochaetus · S. annamicus · S. antarcticus · S. antarticus · S. antipodus · S. apus · S. ardea · S. arechavaletae · S. arenarius · S. arenarius var. arenarius · S. argenteus · S. aristatus · S. articulatus · S. arvensis · S. asiaticus · S. asper · S. asper var. polystachyus · S. atacamensis · S. atacamensis var. exscapus · S. atratus · S. atricha · S. atrichus · S. atripurpureus · S. atrocinctus (Blackgirdle Bulrush) · S. atrocinctus f. brachypodus · S. atrocinctus f. grandis · S. atrocinctus var. brachypodus · S. atrocinctus var. condensatus · S. atrocinctus var. grandis · S. atrofactus · S. atropurpureo-vaginatus · S. atrosanguineus · S. atrovierens · S. atrovirens (Dark Green Bulrush) · S. atrovirens f. angustispicatus · S. atrovirens f. cephalanthus · S. atrovirens f. georgianus · S. atrovirens f. proliferus · S. atrovirens f. sychnocephalus · S. atrovirens f. viviparus · S. atrovirens georgianus · S. attenuatus · S. aturensis · S. aucklandicus · S. auklandicus · S. aureiglumis · S. auro-nitens · S. australiensis · S. australis · S. avatshensis · S. awaczensis · S. bachmannianus

Bibliography

• Bruhl, J. 1995. Sedge genera of the world: Relationships and a new classification of the Cyperaceae. Austral. Syst. Bot. 8: 125-305.
• Goetghebeur, P. 1998. Cyperaceae. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. 4+ vols. Berlin etc. Vol. 4, pp. 141-190.
• Mackenzie, K. K. 1931-1935. Cyperaceae [in part]. In: N. L. Britton et al., eds. 1905+. North American Floraâ¦. 47+ vols. New York. Vol. 18, parts 1-7, pp. 1-478.
• Schuyler, A. E. 1967. A taxonomic revision of North American leafy species of Scirpus. Proc. Acad. Nat. Sci. Philadelphia 119: 295-323.
• Simpson, D. A. and C. A. Inglis. 2001. Cyperaceae of economic, ethnobotanical and horticultural importance: A checklist. Kew Bull. 56: 257-360.
• Strong, M. T. 1994. Taxonomy of Scirpus, Trichophorum, and Schoenoplectus (Cyperaceae) in Virginia. Bartonia 58: 29-68.
• Svenson, H. K. 1957. Cyperaceae. Tribe 2, Scirpeae. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 18, pp. 505-556.
• Tucker, G. C. 1987. The genera of Cyperaceae in the southeastern United States. J. Arnold Arbor. 68: 361-445.

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Notes

Contributors:

• Bisby, F.A., Y.R. Roskov, M.A. Ruggiero, T.M. Orrell, L.E. Paglinawan, P.W. Brewer, N. Bailly, J. van Hertum, eds (2007). Species 2000 & ITIS Catalogue of Life: 2007 Annual Checklist. Species 2000: Reading, U.K.
• Global Biodiversity Information Facility. Accessed November 22, 2007. http://www.gbif.org Mediated distribution data from 15 providers.
• USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL (April 30, 2008)

Data Sources:

Accessed through GBIF Data Portal November 22, 2007:

• Berkeley Natural History Museums, University and Jepson Herbaria DiGIR provider
• Canadian Museum of Nature, Canadian Museum of Nature Herbarium
• Missouri Botanical Garden, Missouri Botanical Garden
• Oregon State University, Vascular Plant Collection
• School of Life Sciences, Arizona State University, Arizona State University Vascular Plant Herbarium
• School of Life Sciences, Arizona State University, The Deaver Herbarium, Northern Arizona University
• USDA PLANTS, USDA PLANTS Database
• University of Alabama Biodiversity and Systematics, Herbarium
• University of Alaska Museum of the North, University of Alaska Museum of the North Herbarium
• University of Washington Burke Museum, Vascular Plant Collection - University of Washington Herbarium
• Utah State University, USU-UTC Specimen Database
• Utah Valley State College
• , Utah Valley State College Herbarium

Identifiers:

• Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 40235
• Global Biodiversity Information Facility Taxonkey: 13752439
• Globally Unique Identifier: urn:lsid:ipni.org:names:313912-1
• U.S.D.A. Plant Symbol: SCRU5
• Zipcode Zoo Species Identifier: 59064

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.
2. Alan T. Whittemore & Alfred E. Schuyler "Scirpus". in Flora of North America Vol. 23 Page 5, 7, 8, 9, 13, 27, 28, 56, 138, 195, 199. Oxford University Press. Online at EFloras.org.