Stems 5–30 cm. Leaf blade 2–5.5 × 1–3.5 mm. Cyathia solitary at distal nodes of stem; peduncle 0.3–0.7 mm. Involucre usually turbinate-campanulate, occasionally suburceolate, 1.1–1.5 × 0.9–1.3 mm; glands sessile, subcircular to slightly elliptic, 0.2–0.5 × 0.3–0.7 mm; appendages absent. Staminate flowers 15–36. Capsules 1.1–1.6 × 1.5–1.8 mm. Seeds with (2–)3(–4) prominent transverse ridges.

Flowering and fruiting summer–late fall. Desert scrub, mostly in calcareous soils; 600–1300 m; Tex.; Mexico (Chihuahua, Coahuila).

Variety theriaca occurs in Brewster and Presidio counties in trans-Pecos Texas.