Contr. Gray Herb. 53: 11. 1918.
Shrubs, dioecious, erect, intricately much branched, mainly 3–15 dm; branchlets terete, becoming rigid and spinose. Leaves short petiolate to sessile; blade ovate-deltate to elliptic or spatulate, (5–)10–27 mm, entire or subhastate. Staminate flowers borne in small axillary glomerules. Pistillate flowers borne solitary or few in bract axils on short, spinose, lateral branchlets of a paniculate inflorescence. Fruiting bracteoles sessile or nearly so, body globose, connate, constricted below oblong to orbicular wings, 7–15 ×3.5–10 mm, entire or obscurely dentate, faces smooth to sparingly cristate. Seeds reddish brown, 2–2.8 mm.
Phenology: Flowering summer–fall.
Habitat: Xeric saline substrates, with mixed salt desert shrubs
Elevation: 30-1300 m
Spiny saltbush apparently forms occasional hybrids with phases of Atriplex canescens, as indicated by the presence of wings on some of the fruiting bracteoles.