Rhynchospora nervosa subsp. ciliata (Vahl) T.Koyama

  • Authority

    Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.

  • Family

    Cyperaceae

  • Scientific Name

    Rhynchospora nervosa subsp. ciliata T.Koyama

  • Description

    Species Description - Cespitose perennial, 10-70 cm tall; rhizomes short; culms obtusely 3-angled, 1-2 mm wide at base, finely ribbed, green, glabrous, or sometimes hirsute below, sheathing base of culms whitened. Leaves 5-15; blades flat or canaliculate, 8-65 cm long, 1.5-4.5 mm wide, finely veined, hirsute beneath, the margins scabrous, basally long-ciliate, the midvein scabrous beneath, the apex narrowly acuminate; sheaths loose, 2-4 mm wide at base, finely veined, light green to straw-colored, whitened at base, hirsute to glabrous. Inflorescence a glomerate head of 5-16 white spikelets, 1-1.5 cm diam.; involucral bracts 7-8, leaflike, longer than the inflorescence, narrowly acuminate at apex, white on upper surface at base, green and glabrous to hirsute beneath at base, the margins scabrous, ciliate at base; spikelets ovate to widely ovate, 5-10 x 2-4 mm, several-flowered; scales 10-30, ovate, boatshaped, keeled above, 3.5-5 x 2-3 mm, glabrous, whitish, frequently red-lineolate, with a narrow pale midrib, extending beyond the acute, obtuse, rounded, or emarginate apex as a short, straight or recurved mucro. Stamens 3, the anthers narrowly linear, 2-3 mm long, bluntly apiculate at apex; styles 2-branched to about one-third length of style, the unbranched portion abruptly expanding below into a shallowly, triangular base, persistent at the summit of the achene. Achene 2-sided, turgid, depressedobovate, 1.8-2.0 x 1.1-1.6 mm, straw-colored to dark yellowish brown, transversely rugulose, the style base about as wide as the achene, convex at summit; bristles absent.

  • Discussion

    Dichromena pura Nees in Mart., Fl. Bras. 2: 112. 1842. Rhynchospora pura (Nees) Griseb., Fl. Brit. W . I. 577. 1864.

    Rhynchospora vahliana Griseb., Fl. Brit. W . I. 577. 1864.

    Rhynchospora ciliata Kiik., Bot. Jahrb. Syst. 56(Beibl. 125): 16. 1921.

    Note: This species was erroneously reported by Woodbury and Weaver (1987) as Dichromena radicans Schltdl. & Cham.

  • Distribution

    Occasional on grassy hillsides and roadside banks. Bordeaux (B562, A3830), Lameshur (W226). Also on St. Thomas; Mexico to South America, and throughout the West Indies.

    Saint Thomas Virgin Islands of the United States South America| México Mexico North America| South America| West Indies|