Herbs, annual, cespitose, 0.03--0.25 dm. Culms to 150, 0.1--0.2 mm wide. Leaves to 0.9 cm, 1/4--1 times height of plant. Inflorescences terminal solitary flowers; bracts subtending inflorescence (1--)2, ovate, inconspicuous, 0.3--0.9 mm, membranous, apex acute. Flowers 3-merous; : tepals (4--)6(--8), turning inward to enwrap shorter capsule at maturity, chestnut brown to black, lanceolate to oblong, 1.2--2.3(--2.8) ã  0.4--0.6 mm; ; outer and inner series nearly equal, acute to acuminate; stamens 3, filaments 0.3--0.6 mm, anthers 0.15--0.25 mm; style 0.1 mm, stigma 0.2--0.3 mm. Capsules pale reddish, 3-locular, ovoid to ellipsoid, 1--1.9 mm  ã 0.5--1 mm. Seeds ovoid to globose, 0.3--0.5 mm. 2n = ca. 38. Flowering and fruiting spring--mid summer. Usually fine, sandy soil of washes, swales in meadows, and seepage areas on rock outcrops; 600--3600 m; Calif., Colo., Idaho, Nev., Oreg., Utah; Mexico.