Rhynchospora

  • Authority

    Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.

  • Family

    Cyperaceae

  • Scientific Name

    Rhynchospora

  • Description

    Genus Description - Spikelets lanceolate, ovate, or elliptical, slightly bilaterally compressed or terete. Glumes few to many, distichously disposed or imbricated on a continuous simple axis, membranous to herbaceous, 1-nerved, brown or white; basal 1 to few empty and much smaller than flower-bearing ones; middle 1 to several bearing a hermaphrodite flower at axil, all or part of these fruit-bearing; upper glumes hyaline, narrower and longer than fruit-bearing ones, staminate with or without abortive pistil; distal glumes much reduced. Flowers hermaphrodite or staminate. Hypogynous bristles 0 to 6, rarely more than 6, upwardly or retrorsely scabrous, sometimes plumose on lower part, rarely nearly smooth. Stamens 2 or 3. Achenes lenticular, smooth, cancellated, rugose, spinose, or sometimes becoming concave-convex with strongly incurved margins; style-base spongy thickened, conical, depressed conical or lunate, truncate or more or less lobed at base; style slender, the apex 2-fid (with 2 stigmas) or undivided. Perennial or occasionally annual sedges of varying size. Culms central, scapelike to nodose and leaved at nodes. Leaves radical and/or cauline; leaf-blades linear to lanceolate, folded or flattish with 1 or 3 costas, or canaliculate without distinct costa; sheaths closed without ligule. Inflorescences of varying types, mostly consisting of terminal and lateral partial corymbs or panicles, sometimes with few to many heads disposed in corymbs, spikes, or in panicles, rather often whole inflorescence reduced to a single terminal head.

  • Discussion

    [Phaecocephalum Ehrhart, Beitr. Naturk. 4: 146. 1789. Name only. Type species. Schoenus fuscus L. = Rhynchospora fusca (L.) Aiton f.].

    Dichromena Michaux, Fl. Boreal.- Amer 1: 37. 1803. Type species. Dichromena leucocephala Michaux = Rhynchospora stellata (Lamarck) Grisebach; = Dichroma Persoon, Syn. PI. 1: 57. 1805. Sphalmate.

    [Triodon L. C. Richard ex Persoon, Syn. PI. 1: 60. 1805. In note. Nomen rejiciendum; = Rhynchospora setacea (Rottböll) Böckeler].

    Spermodon P. Beauvois in Lestiboudois, Ess. Fam. Cyp. 27. 1819. Type species. Spermodon setaceus (Rottböll) Nees = Rhynchospora setacea (Rottböll) Böckeler.

    Zosterospermum P. Beauvois in Lestiboudois, Ess. Fam. Cyp. 28. 1819. Type species. Zosterospermum gracile Hamilton = Rhynchospora rugosa (Vahl) S. Gale.

    Haplostylis Nees, Linnaea 9: 295. 1834. Type species. Haplostylis barbata (Vahl) Nees = Rhynchospora barbata (Vahl) Kunth.

    Calyptrostylis Nees, Linnaea 9: 295. 1834. Type species. Calyptrostylis rudgei Nees = Rhynchospora gigantea Kunth.

    Mitrospora Nees, Linnaea 9: 295. 1834. Type species. Mitrospora recurvata Nees = Rhynchospora recurvata (Nees) Steudel.

    Cephaloschoenus Nees, Linnaea 9: 295. 1834. Type species. Cephaloschoenus globosus (H. B. K.) Nees = Rhynchospora globosa (H. B. K.) Romer & Schultes; = Exphaloschoenus Nees in Hooker, Jour. Bot. 2: 398. 1840. Sphalmate.

    Morisia Nees, Linnaea 9: 295. 1834. Type species. Morisia capitata Nees = Rhynchospora rubra (Loureiro) Makino.

    Ceratoschoenus Nees, Linnaea 9: 296. 1834. Type species. Ceratoschoenus corniculatus (Lamarck) Nees = Rhynchospora comiculata (Lamarck) A. Gray.

    Diplochaeta Nees, Linnaea 9: 296. 1834. Type species. Diplochaeta guianensis Nees = Rhynchospora pterocarpa Römer & Schultes.

    Haloschoenus Nees, Linnaea 9: 296. 1834. Type species. Haloschoenus capillaris Nees = Rhynchospora tenuis Link.

    Echinoschoenus Nees & Meyen ex Nees, Linnaea 9: 297. 1834. Type species. Echinoschoenus sparganioides Lindley ex Nees = Rhynchospora exaltata Kunth.

    Psilocarya Torrey, Ann. Lyceum N. Y. 3: 359. 1836. Type species. Psilocarya scirpoides Torrey = Rhynchospora scirpoides (Torrey) Grisebach.

    [Lonchostylis Torrey, Ann. Lyceum N. Y. 3: 370. 1836. In note; illegitimate name.]

    Leptoschoenus Nees in Hooker, Jour. Bot. 2: 393. 1840. Type species. Leptoschoenus prolifer Nees = Rhynchospora schomburgkiana (Böckeler) T. Koyama.

    Ephippiorhynchium Nees, Fl. Brasil. 2(1): 110. 1842. Type species. Ephippiorhynchium polycephalum Nees = Rhynchospora polycephala Kunth; = Rhynchospora holoschoenoides (L. C. Richard) Herter.

    [Pachymitra Nees, Fl. Brasil. 2(1): 115. 1842. Invalid name pubished as a synonym. Type species. Pachymitra vellutina Nees = Rhynchospora vellutina (Kunth) Böckeler.]

    Asteroschoenus Nees, FI. Brasil. 2(1): 124. 1842. Type species. Asteroschoenus rigidus (Kunth) Nees = Rhynchospora consanguinea (Kunth) Bockeler.

    Ptilochaeta Nees, Fl. Brasil. 2(1): 147. 1842. Type species. Ptilochaeta diodon Nees = Rhynchospora diodon (Nees) Böckeler.

    Hygrocharis Nees, Fl. Brasil. 2(1): 147. 1842. In footnote. Type species. Rhynchospora kunthii Nees.

    Sphaeroschoenus Nees, Nov. Act. Nat. Cur. 19, Suppl. 1: 97. 1843. Type species. Sphaeroschoenus wallichii Nees = Rhynchospora rubra (Loureiro) Makino.

    Ptilosciadium Steudel, Syn. Pl Glumac. 2: 149. 1855. Type species. Ptilosciadium lindenii Steudel = Rhynchospora hirta (Nees) Böckeler.

    Calyptrolepis Steudel, Syn. Pl. Glumac. 2: 151. 1855. Type species. Calyptrolepis junciformis Steudel = Rhynchospora oligantha A. Gray.

    Trichochaeta Steudel, Syn. Pl. Glumac. 2: 155. 1855. Type species. Trichochaeta tenuis Steudel = Rhynchospora trichochaeta C. B. Clarke.

    [Cleistocalyx Steudel, Syn. PI. Glumac. 2: 229. 18SS. Invalid name published as a synonym. Type species. Cleistocalyx junciformis Steudel = Rhynchospora oligantha A. Gray.]

    Type. Rhynchospora alba (L.) Vahl. [= Schoenus albus L.]

  • Distribution

    Distribution. About 250 species widely distributed in all world, from tropics to subartic regions, with a great concentration of species in tropical and subtropical North and South America.