Young stems densely white-tomentulose, becoming canescent. Leaves: petiole (4–)6–16(–22) mm; blade bicolor, abaxially white, adaxially green and nonlustrous, linear to linear-lanceolate, (2.5–)5–11(–l5) × (0.6–)0.7–1.2(–1.4) cm, surfaces villous-tomentulose, soon or tardily glabrescent except for hairy midveins. Corymbs 1.5–4.5 × 2–6.5 cm, ˂villous to tomentulose˃. Flowers: hypanthium 2–2.5 × 3–3.5 mm, exterior white villous-tomentulose, interior glabrous except at base; sepals 1.3–1.8 × 1.6–2 mm, villous-tomentulose; petals 4–5 × 2.4–3 mm; filaments 3–5 mm. Capsules 5–6 × 3.5–4 mm. Seeds 3.5–4 × 0.9–1.2 mm.

Flowering spring. Canyon margins and hillsides of the Sonoran Desert; 700–1500 m; Ariz.; Mexico (Baja California).

Subspecies sonorensis is known from the Ajo Mountains in Pima County. Some plants from the Baboquivari Mountains of Pima County have somewhat similar narrow leaves but lack the dense vestiture on stems, inflorescences, and abaxial leaf surfaces.