Annual herb, tufted or solitary 20 cm - 1 m tall Leaves: alternate, three-ranked, 1 - 5 mm wide, flat basally, linear with a tapering and three-sided tip, parallel-veined, with a sheathing base that encloses the stem. Sheaths opening at the top. Inflorescence: a loosely clustered group of one to five spikelet clusters, terminal and axillary, subtended by leaf-like bracts. Spikelet clusters cylindrical to egg-shaped. Flowers: minute, subtended by a floral scale, lacking sepals and petals. Stamens one or two, exserted. Pistil one. Style two-cleft. Fruit: a one-seeded achene, scarcely stalked, dark brown, to 1 mm long (not including tubercle) and 1 mm wide, more or less round, biconvex, wrinkled. Tubercle tiny, flattened, triangular with a broadly two-lobed base, appressed. Culm: upright, 20 cm - 1 m long, nearly circular in cross-section or angled, ribbed, solid, leafy. Spikelets: dark brown, 4 - 6 mm long, lance-shaped to egg-shaped with a pointed apex. Floral scales spirally arranged and overlapping, 2 - 3.5 mm long, egg-shaped with a pointed apex, one-ribbed, thin.
Similar species: No information at this time.
Habitat and ecology: Known only from Porter County, Indiana and likely extirpated in the Chicago Region. Found in wet sandy soil.
Occurence in the Chicago region: native
Etymology: Rhynchospora comes from the Greek words rhynchus, meaning beak, and spora, meaning seed, referring to the beaked achene. Nitens means shining.
Much like no. 1 [Rhynchospora scirpoides (Torr.) Griseb.]; achene scarcely stipitate, transversely conspicuously rugose, only inconspicuously margined; tubercle very short and closely appressed. Wet sandy soil and bogs; se. Mass. to Tex.; nw. Ind. (Psilocarya n.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.