Enum. Pl. 2: 539. 1837.
Plants perennial, cespitose, 10–100 cm; rhizomes absent. Culms erect or excurved, leafy, obscurely trigonous, slender, firm. Leaves shorter than culms; blades spreading to ascending, linear, proximally flat, 2–4 mm wide, apex involute, then trigonous, subulate. Inflorescences: spikelet clusters 1–4, loose to dense, broadly turbinate, lobed or hemispheric; peduncles and branches ascending; leafy bracts exceeding proximal, sometimes distal, clusters. Spikelets light redbrown, ellipsoid or narrowly ovoid, 4–5 mm, apex acute to acuminate; fertile scales broadly ovate, 3.5–4.5 mm, apex acute or acuminate, apiculate. Flowers: perianth bristles mostly 6, reaching from fruit midbody to tubercle tip or beyond, antrorsely barbellate. Fruits 1(–2) per spikelet, 2.5–3 mm; body dark brown, broadly, tumidly obovoid, 2–2.5 × 2–2.5 mm, apically buttressed to tubercle; surfaces finely transversely rugulose or nearly level, with fine transverse rows of pits or low papillae, often appearing nearly smooth; tubercle lowconic, 0.4–0.6 mm, apiculate.
Phenology: Fruiting spring–summer.
Habitat: Sandy pinelands and sandhills, particularly in longleaf pine type
Elevation: 0–300 m
Ala., Fla., Ga., La., Miss., N.C., S.C., Tex., Va., West Indies.
Of all North American species of Rhynchospora, R. grayi appears best adapted to the xeric conditions found in the coarser sands of the longleaf pine-scrub oak–dominated yellow sandhills. Interestingly, it seems seldom to mix with its closest relative, R. megalocarpa, which is more often found in white sandhills.