Plants annual; taproot filiform to slender. Stems erect to ascending, much-branched, 15-33 cm, glabrous to minutely puberulent. Leaves: stipules lanceolate to ovate, 2.5-5 mm, apex acuminate to long-acuminate, entire; blade linear to filiform, 8-15 × 0.4-0.8 mm, leathery, apex acute to submucronate, glabrous. Cymes terminal and axillary, 5-20+-flowered, dichotomous, repeatedly branching and diffusely spreading, open, clusters 0.5-1.5 mm wide. Flowers 5-merous, short-campanulate, with enlarged hypanthium and calyx slightly constricted proximally, 1.6-2 mm, appressed-puberulent proximally; sepals red-brown, midrib and lateral pair of veins absent to evident, oblong, 0.8-1.1 mm, leathery to rigid, margins whitish to translucent, 0.05-0.1 mm wide, scarious, apex terminated by awn, hood present, broadly rounded, awn divergently spreading, 0.4-0.6 mm, ± broadly conic in proximal 1/ 2 with pale-yellow, scabrous spine; staminodes filiform, 0.5-0.7 mm; style 1, cleft in distal 1/6, 0.6-0.7 mm. Utricles ovoid-globose, 0.8-0.9 mm, smooth, glabrous.

Flowering summer-fall. Rocky places on limestone hills and high prairies; 100-600 m; Tex.