Rhynchospora microcephala

Plants perennial, cespitose, 30-90 cm; rhizomes absent. Culms arching or erect, leafy, nearly terete, multiribbed, slender. Principal leaves overtopped by culm; blades linear, proximally flattened, 1-3 mm wide, apex tapering, trigonous. Inflorescences: spikelet clusters 2-6, mostly widely spaced; clusters dense, hemispheric to mostly spheroid, 0.5-1 cm thick. Spikelets dark red brown to dark brown, lance ovoid, (2-)2.5-3.5(-4) mm, apex acute; fertile scales elliptic, 2-3 mm, apex acute, midrib short excurrent or not. Flowers: perianth bristles 6, reaching tubercle tip, retrorsely barbellate. Fruits 1 per spikelet, 2.5-3 mm; body pale brown with light center, lenticular, obovoid distal to stipe, 1.1-1.5 × 0.9-1.1 mm, margins pale, wirelike, surfaces slick; tubercle triangular subulate, 0.9-1.2(-1.5) mm, at least 0.5 mm wide at base.

Fruiting summer-fall. Sands and sandy peats of savanna swales, pineland seeps, bogs, ditches, pond shores and banks; 0-200 m; Ala., Del., D.C., Fla., Ga., La., Md., Miss., N.J., N.C., S.C., Va.; West Indies (Cuba).