Rhynchospora microcephala (Britton) Britton

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.

Ala., Del., D.C., Fla., Ga., La., Md., Miss., N.J., N.C., S.C., Va.; West Indies (Cuba).

Fruiting summer–fall.

Sands and sandy peats of savanna swales, pineland seeps, bogs, ditches, pond shores and banks; 0–200m.

Rhynchospora axillaris (Lamarck) Britton var. microcephala Britton, Trans. New York Acad. Sci. 11: 89. 1892 (as Rynchospora); R. cephalantha A. Gray var. microcephala (Britton) Kükenthal

Rhynchospora microcephala là loài thực vật có hoa trong họ Cói. Loài này được (Britton) Britton miêu tả khoa học đầu tiên năm 1903.