Schoenus juncoides Vahl, Enum. Pl. 2: 211. 1805; Bulbostylis arenaria (Nees) Lindman; B. argentina Palla; B. langsdorffiana (Kunth) C. B. Clarke; Fimbristylis capillaris (Linnaeus) A. Gray var. pilosa Britton; F. juncoides (Vahl) Alain; F. savannarum Alain; Oncostylis arenaria Nees; O. tenuifolia (Rudge) Nees var. hirta Liebmann; O. tenuifolia var. nana Liebmann; Scirpus lorentzii Boeckeler

Herbs, perennial, densely cespitose. Culms 10–30(–40) cm, bases hard, swollen. Leaves ¼–1/2 length of scapes; sheaths brown to stramineous, abaxially glabrous or hirtellous; blades spreading to erect, filiform, wiry, less than 1 mm wide, involute, margins and adaxial surface glabrous to hispidulous or scabrid. Inflorescences terminal, mostly in compound, compact or diffuse, involucrate anthelae; scapes ascending to erect, wiry, 1 mm thick, coarsely ribbed, ribs glabrous or hispidulous to scabrid; proximal bladed involucral bract exceeding or exceeded by inflorescence. Spikelets red-brown to chestnut-brown, lanceoloid to cylindric, 4–6 mm, mostly longer than broad; fertile scales ovate, curvate-keeled, 2–2.5 mm, apex acute, glabrous or papillose-puberulent, midrib excurrent as mucro or mucronula. Flowers: stamens 3; anthers linear, 1–2 mm. Achenes gray to yellow-brown or dark brown, trigonous-obovoid, 1–1.2(–1.5) mm, faces rugulose, papillate; tubercle a globose button. 2n = 60.

Fruiting all year. Savanna, prairie, steppes, basic and acidic rock outcrops, mostly higher elevations; 100–3000 m; Ariz., N.Mex., Tex.; Mexico; West Indies; Central America; South America.

Bulbostylis juncoides is unquestionably the most polymorphic species of its complex in Bulbostylis and with a potential synonymy more elaborate than given here.