Plants perennial, cespitose, 20-50 cm, wiry; rhizomes absent. Culms erect to spreading, leafy based; scapes nearly filiform, nearly trigonous, few ribbed. Leaves spreading to erect, exceeded by scape; blades filiform to linear, proximally flat or involute, becoming involute, 0.4-2 mm wide, apex tapering, trigonous. Inflorescences terminal, solitary, headlike, dense, white, leafy involucrate, 0.5-1 cm wide; involucral bracts 3-6, spreading to recurved, white based, green tipped, narrowly linear, longest bract elongate subulate, 4-8 cm × 2-5 mm. Spikelets white, ovoid, 4-6 mm; scales several, boat shaped, basal ones with ciliolate keel, fertile ones 3-3.8 mm. Flowers: perianth absent. Fruits 1-1.2 mm; body yellow to black, nearly orbicular, tumidly lenticular, 0.8-1 × 0.6-0.7(-1) mm; surface lattices short linear, vertical in fine undulating rows, with ends raised to rounded, transverse rugulosities; tubercle low triangular, lunate, 0.2-0.3 mm, apex acute, blunt or apiculate.

Fruiting spring-fall, or all year. Moist open areas over reef limestones, rocky pine savanna; 0-50 m; Fla.; Mexico (Chiapas, Yucatán); West Indies (Bahamas); Central America (Belize).

Rhynchospora floridensis is much like R. colorata, with which it is often associated; it can be easily distinguished by its strictly cespitose habit and its ciliolate spikelet scale keels.