Herbs, perennial, cespitose, to 8 dm. Rhizomes densely branching. Cataphylls 1--2. Leaves basal, 2--5; auricles 0.4--1.1(--2) mm, scarious; blade flat, 9--25 cm x 0.8--1.5(--2.4) mm, margins entire wide, becoming involute under xeric conditions. Inflorescences 10--150-flowered, usually congested, 1.5--8 cm; primary bract usually longer than inflorescence. Flowers: bracteoles 2; tepals green to tannish, lanceolate, 3.5--5.7 mm; outer and inner series nearly equal, in fruit apex appressed to capsule; stamens 6, filaments 0.6--1.1 mm, anthers 0.56--0.91 mm; style 0.2 mm. Capsules dark tan to reddish brown, 3-locular, ellipsoid to narrowly so, 2.6--4.7 x 1.3--2 mm, barely shorter than tepals. Seeds tan, ellipsoid to lunate, (0.32--)0.45--0.52(--0.65) mm, not tailed. 2n = ca. 80. Flowering and fruiting late spring--early summer. Exposed moist or wet soils associated with depressions in temporal wetlands, along stream banks or lake shores especially in sandy soils; 900--1650 m; Ark., Calif., Idaho, Kans., La., Mo., Mont., Nebr., Okla., Oreg., Tex.as, Wash.
Stems cespitose from a short rhizome, 3-5 dm; lvs on the basal part of the stem, the sheaths projecting into prominent, firmly membranous auricles, the blades thick but ±flattened, ca 1-1.5 mm wide; infl (2-)3-6(-7) cm, loose to compact, usually somewhat surpassed by the invol bract; fls numerous, prophyllate; tep pale greenish to stramineous, lance-subulate, long-acuminate and pungent, the pet 3.5-4 mm and evidently scarious-margined, the sep less so, 4-5.5 mm, ±closely investing the fr; stamens 6; fr trilocular, oblong-ovoid, 3.7-4.6 mm, truncate, ca equaling the pet but shorter than the sep; seeds 0.5 mm, merely apiculate, becoming mucilaginous when wetted. Sandy prairies and sandstone glades; Mo. and w. Ark. to Neb., Kans., Okla., and ne. Tex.; disjunct in Oreg., Wash., and n. Idaho. (J. kansanus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.