Shrubs, 20-80(-150+) cm. Stems erect. Leaves mostly alternate; petioles 0; blades mostly filiform, 15-35(-65+) × 0.5-1.5 mm, sometimes with 3(-5+) filiform lobes, abaxial faces sparsely scabrellous, glabrescent, often vernicose, adaxial faces densely scabrellous (white). Pistillate heads ± intermixed with staminates; florets 1. Staminate heads: peduncles 0-0.5 mm; involucres ± cup-shaped, 1-3(-4) mm diam., ± glabrate, ± vernicose or gland-dotted; florets 5-15+. Burs: bodies plumply fusiform, 3-4(-6) mm, stipitate-glandular, wings 5-20+, ± scattered, broadly cuneiform, flabellate, or orbiculate, 3-4(-6) × 2-4(-8) mm. 2n = 36. Flowering Mar-May(-Jun). Desert washes, sandy and gravelly benches, lava talus; 200-1800 m; Ariz., Calif., Nev., Utah; Mexico (Baja California, Sonora). Variety salsola refers to plants bearing burs with 6-14 wings in 2-3+ cycles, their tips ± spreading to patent; var. pentalepis (Rydberg) Strother & B. G. Baldwin refers to plants bearing burs with 5-9(-13) wings in 1(-2) cycles, their tips ± spreading to patent; var. fasciculata (A. Nelson) Strother & B. G. Baldwin [= Hymenoclea salsola var. patula (A. Nelson) K. M. Peterson & W. W. Payne, an illegitimate name] refers to plants bearing burs with 10-18 wings in 2-3+ cycles, their tips antrorsely ± appressed (see K. M. Peterson and W. W. Payne 1973).

Hybrids between Ambrosia salsola and A. dumosa have been called A. ×platyspina (Seaman) Strother & B. G. Baldwin.