Plants perennial, densely cespitose or solitary, 10-100 cm; rhizomes absent. Culms mostly lax, ascending to leaning excurved, leafy, linear to filiform, terete. Leaves shorter than culm; blades ascending, filiform to narrowly linear, proximally flat, 0.5-1.5(-2.5) mm wide, margins distally strongly involute, apex trigonous, tapering. Inflorescences: spikelet clusters 1-3(-4), proximalmost distant, dense to sparse, narrowly turbinate to hemispheric; peduncles and branches ascending; leafy bracts linear setaceous, mostly overtopping clusters. Spikelets red brown, ovoid to lanceoloid, (3.5-)4-5 mm, apex acute; fertile scales ovate, 3-4.5 mm, apex acute, mucronate to awned cuspidate. Flowers: bristles 6, mostly reaching tip of tubercle or beyond, antrorsely barbellate. Fruits 1-3 per spikelet, (2.5-)3-3.5(-4.1) mm; body dark brown with small pale center, lenticular, broadly ellipsoid to suborbicular, 1.3-2.1 × 1.3-1.5 mm, smooth, margins narrow, flowing into tubercle; tubercle triangular-subulate, compressed, mostly 1.5-2 mm. Fruiting late spring-fall. Moist to wet sandy peaty substrates in ditches, bogs, seeps, wet savannas, barrens, and flatwoods; 0-400 m; Ala., Ark., Del., Fla., Ga., La., Md., Miss., N.J., N.C., Okla., Pa., S.C., Tenn., Tex., Va.; West Indies (Cuba); Central America. Through the southern coastal plain are wider leaved examples of Rhynchospora gracilenta that are sparingly cespitose to solitary-stemmed, often with but a single terminal inflorescence with dense clusters of spikelets (var. diversifolia). That would be a tenable designation were it not for the large numbers of populations with intermediate habit.
Cespitose, to 1 m; lvs filiform or to 2 mm wide; terminal glomerule ovoid to subglobose, 6-12 mm wide; lateral glomerules 1-2, short-peduncled; spikelets 3-3.5 mm, castaneous, with 2-3 fls and 1-2 frs; bristles 6, 1.8-3.4 mm, antrorsely barbellate; achenes ellipsoid to rotund, dull brown, often with a pale central spot, 1.3-1.7 mm, two-thirds to fully as wide; tubercle flat-subulate above a triangular base, 1-2 mm, bogs and wet soil on the coastal plain; N.J. to Fla. and Tex.; rarely inland from w. Va. s. and w.; Mex. and C. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.