Juncus interior Wiegand

Herbs, perennial, tufted, 2--6 dm. Rhizomes densely branching. Culms 1--10. Cataphylls 1--3. Leaves basal, 1--2(--3); auricles whitish or purplish tinged, 0.2--0.4(--0.6) mm, scarious; blade flat, 5--15 cm x 0.5--1.1 mm, margins entire. Inflorescences usually somewhat compact, 1.5--7 cm; primary bract usually shorter than inflorescence. Flowers: bracteoles 2; tepals greenish, lanceolate, 3.3--4.4 mm, apex acuminate; stamens 6, filaments 0.5--0.9 mm, anthers 0.4--0.6 mm; style 0.1--0.2 mm. Capsules light tan or darker, 1-locular to pseudo-3-locular, ellipsoid to nearly globose, (3.3--)3.8--4.7 mm, nearly equal to or longer than tepals. Seeds tan, ellipsoid to lunate, 0.436--0.73 mm, not tailed. 2n = 80.

Flowering and fruiting late spring--early summer. Dry, often upland sites in prairies, exposed disturbed sites, and ditches in sandy or clayey soils; Alta., Man., Ont., Que., Sask.; Ariz., Ark., Colo., Ill., Ind., Iowa, Kans., Ky., La., Minn., Mont., Mo., Nebr., N.Mex., N.Dak., Ohio, Okla., S.Dak., Tenn., Tex.as, Utah, Wis., Wyo.

Juncus arizonicus Wiegand; J. interior var. arizonicus (Wiegand) F. J. Hermann; J. interior var. neomexicanus (Wiegand) F. J. Hermann; J. monostichus Bartlett; J. neomexicanus Wiegand