Plants annual, cespitose or solitary, (10-)20-100 cm; rhizomes absent. Culms erect, leafy, nearly terete or angled, many ribbed. Principal midculm leaves often exceeding inflorescences; blades linear, proximally flattened, 1-5 mm wide, apex trigonous, tapering. Inflorescences terminal and axillary, clusters of corymbs 1-5, usually diffuse; leafy bracts exceeding proximal corymbs. Spikelets dark brown, lanceoloid to ovoid, mostly 4-6(-8) mm, apex acute; fertile scales many, ovate, rounded-convex, 2-3.5 mm, apex acute, midrib mostly included, rarely forming apiculus. Flowers: perianth absent. Fruits 1-1.3(-1.5) mm, body dark brown, tumidly lenticular, nearly orbicular, 0.7-1 × 0.7-1 mm, margins strong, interrupted at tubercle base; surfaces irregularly transversely rugulose with wavy rows of vertical, linear, raised cells; tubercle depressed-triangular, 0.1-0.3 mm, capping fruit summit, base broadly 2 lobed.
Fruiting summer-fall or all year. Moist to wet sands or peats of stream banks, pond shores, depressions in savannas, marshes; 0-100 m; Ala., Del., Fla., Ga., Ind., La., Mass., Mich., Miss., N.J., N.Y., N.C., S.C., Tex., Va.; West Indies; Central America.
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.
Author: The Morton Arboretum
In sandy soil on the borders of sloughs. My only specimen is one collected by Umbach on the border of a slough at Dune Park, Porter County, in 1899. Evidently it is very local.
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.
©The New York Botanical Garden. All rights reserved. Used by permission.
