Plants annual, herbaceous, glabrous or sparsely glandular, not glaucous. Stems erect, simple or dichotomously branched, 3-25(-30) cm. Leaves mostly appearing whorled; stipules ± persistent, simple, filiform to subulate, 0.5-2 mm; petiole absent or nearly so; blade linear, 1-3(-3.5) cm × 0.5-1.5(-2) mm, base attenuate, apex rounded, sometimes apiculate. Inflorescences terminal or racemose, open, 3-30+-flowered cymes. Pedicels shorter to longer than subtending bracts at maturity. Flowers: sepals with midvein prominent, lateral pair often evident, then arcing outward at midsection and confluent apically, broadly ovate to ± orbiculate (herbaceous portion elliptic to oblong or lanceolate), 2-3.5 mm, subequal, apex obtuse (herbaceous portion similar), hood oblique or at right angles to apex, formed in part by scarious margins, glabrous; petals 4-fid for 2 or less their length, 1.7-2.5 mm, subequal to sepals, lobes 1-veined, vein unbranched, linear, outer pair 1/ 1/ 2 as long as petal trunk, inner pair slightly shorter or, sometimes, greatly reduced or absent, trunk laterally denticulate, base abruptly tapered, apex rounded. Seeds dark brown to purplish, horseshoe-shaped, 0.8-0.9 mm; tubercles minute, rounded. Flowering late summer-early fall. Rocky to sandy soil; 2100-2400 m; Ariz., N.Mex., Tex.; Mexico.