Cyperus planifolius Rich.

  • 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

    Cyperus planifolius Rich.

  • Description

    Species Description - Robust perennial, 0.4-1 m tall; rhizome short and thick; culms 3-angled, (1.5-)2-4(-5) mm wide at base, smooth, the sheathing base 1-2.5 cm wide. Leaves many; blades stiff, flattish, crowded at base, 50-90 cm long, (5-)6-10(-13) mm wide, glaucous, scabrous on margins and midvein beneath, septate, sometimes obscurely so, frequently pale beneath, the surface reddish brown, lineolate, long-acuminate to obtuse tip; sheaths distinctly fineveined, reddish to purple-brown, glabrous, eligulate, the inner band finely veined. Inflorescence an open, compound umbel-like corymb or rarely congested in 1 or 2 headlike clusters, (5-) 10- 20 cm diam.; involucral bracts 6-9, leaflike, the lowest 18-50 cm long, 4-10 mm wide, the upper linear, subulate; rays (6-)8- 9(-12), unequal, obscurely 3-angled to slightly compressed, to 13 cm long, 0.6-1.2 mm wide, bearing clusters of spikes at apex, the primary thicker rays elongate, ascending, the secondary rays when present short, the lateral rays (just below the base of the central, subsessile spike) divergent to reflexed at maturity; spikes broadly ovate to broadly oblong-ovate, 1.3-2.5 x 1.5-2.8 cm; spikelets 6-30, narrowly linear, 6-15(-20) x 1.4-1.8 mm, spreading, falling entire, the lower ones divergent to reflexed at maturity; rachilla broadly winged, with 7-29 flowers; scales ovatelanceolate, acutely keeled, 2.8-3.5 x 1.4-2.0 mm , 9-11-nerved, membranous, pale brown to reddish brown, with scarious margins, the narrow, 3-nerved keel ending in a short mucro below the acute apex. Stamens 3, the anthers ca. 1 mm long, with a minute, triangular, black appendage at apex; styles 3-branched to below the middle. Achene 3-angled, obovoid to obovoid-ellipsoid, 1.4-1.6 x 0.8-0.9 mm , with flat to slightly convex sides, blackish at maturity, minutely puncticulate.

  • Discussion

    Cyperus purpurascens Vahl, Enum. PL 2: 359. 1806. Mariscus purpurascens (Vahl) C.B. Clarke in Urb., Symb. Ant. 2(1): 51. 1900.

    Cyperus brunneus sensu Griseb., Fl. Brit. W . I. 565. 1864, in part, non Sw., 1797.

  • Distribution

    Occasional in scrubs and dry coastal forests. Southside Pond (A1831). Also on St. Croix, St. Thomas, Tortola, and Virgin Gorda; Cuba, Hispaniola, Jamaica, Puerto Rico, and the Lesser Antilles.

    Saint Thomas Virgin Islands of the United States South America| Saint Croix Virgin Islands of the United States South America| Virgin Gorda Virgin Islands South America| Cuba South America| West Indies| West Indies| Jamaica South America| Puerto Rico South America| West Indies|