Stems yellow to pale orange, slender. Inflorescences loose, umbelliform; bracts at base of clusters 1, at base of pedicels 0 or 1, ovate-lanceolate, mem­branous, ± reticulate, shiny, margins entire, apex acute. Pedicels (1–)2–3(–5) mm, papil­late. Flowers (3 or)4-merous, 2.8–4 mm, calyx and corolla papillate; calyx straw yellow, cylindric, equaling corolla tube length, divided 3/4 its length, ± reticulate, shiny, lobes ovate-triangular, bases not overlapping, margins entire, midvein not carinate, sometimes with multicellular protuberances, apex acute to acuminate; corolla white, drying creamy white, 3–3.6 mm, tube cylindric, 1.5–2 mm, not saccate, lobes spreading or reflexed, lanceolate, equaling corolla tube length, margins entire, apex acute, straight; infrastaminal scales truncate to slightly obovate, 0.8–1.2 mm, 1/4–1/3 corolla tube length, bridged at 0.1–0.2 mm, distally fimbriate, fimbriae 0.1–0.2 mm; stamens exserted, shorter than corolla lobes; filaments 0.5–0.8 mm; anthers 0.3–0.5 × 0.2–0.3 mm; styles filiform, 0.8–2.5 mm, longer than ovary. Capsules globose to depressed-globose, 1.5–2.2 × 0.7–1.5 mm, thickened and slightly raised or with 2–4 protuberances around relatively small interstylar aperture, translucent, capped by withered corolla, dehiscence circumscissile. Seeds 2–4, angled, subglobose to broadly elliptic, 0.8–1.1 × 0.7–0.8 mm, hilum subterminal.

Flowering Jul–Feb. Host: Euphorbia subg. Chamae­syce; 30–1700 m; Ariz., N.Mex., Tex.