Vahl, Enum. Pl. 2:321.1806 Perennial, 30-60 cm tall; culms slender. Leaves linear, 4-12 mm wide, the underside of midrib and the margins scabrid. Inflorescences subtended by several, long, leaflike bracts, compound; spikelets both at base of inflorescence and on long, spreading rays, the ultimate clusters forming simple umbels, greenish, 10-24-flowered, 5-15 (20) mm long; scales green only on keel, with a narrow, incurved tip. Achenes obovate to globose, brown, trigonous with concave sides, smooth, 1-1.5 mm long. Croat 6912. Abundant in clearings, especially near the laboratory. Apparently flowers throughout the year. Throughout warmer regions of Western and Eastern Hemispheres. In Panama, widespread and ecologically variable; known from tropical moist forest all along the Atlantic slope as well as in Chiriqui, Herrera, Panama, and Darien, from tropical dry forest in Panama (Taboga Island), from premontane moist forest in the Canal Zone and Panama, from premontane wet forest in Chiriqui, Coclé, Panama, and Darien, from tropical wet forest in Panama and Darien, and from lower montane wet forest in Chiriqui.