Herbs, annual. Stems erect, ascending, or procumbent, much branched, obtusely angled, 1-6 dm, stout, scurfy when young. Leaves alternate or proximalmost opposite or subopposite; petiole to 1.5 cm or sessile; blade paler abaxially, oblong or oval, lanceolate, or elliptic to broadly obovate or narrowly oblong, 10-40(-60) × (2-)4-20 mm, base rounded to cuneate, margin entire or undulate, rarely with 1-2 teeth, apex rounded to acute, mucronate, thin, often densely white scurfy beneath, grayish green and glabrate above. Staminate glomerules terminal or in dense or interrupted, terminal or axillary, naked spikes or shortly branched panicles. Pistillate flowers fascicled in axils. Fruiting bracteoles subsessile or with stipes to 1 mm, cuneate-orbiculate, compressed, 4.5-7 × 3.5-5.6 mm, typically longer than wide, united to middle, apex rounded, 3-5-toothed, teeth subequal, sides irregularly tuberculate or with 2 lateral dentate crests, rarely not appendaged. Seeds reddish brown, 2 mm. 2n = 18.
Flowering summer-fall. Sandy seashores, salt marshes; 0 m; Ala., Fla., La., Md., Mass., Miss., N.H., N.J., N.C., Tex., Va.
Problems with prior applications of the name Atriplex mucronata lie in the mistaken determination of the place of publication as Amer. Monthly Mag. & Crit. Rev. 2: 176. 1818 (where the name is only mentioned), instead of 2: 119. 1817 (where accompanied by a description and notes). H. M. Hall and F. E. Clements (1923) evidently relied on P. C. Standley´s (1916) interpretation, which indicated the wrong citation (see also A. dioica Rafinesque as an identical example). Hall and Clements applied the name mucronata to their interpretation of A. patula subsp. hastata or to A. hastata (i.e., to A. prostrata according to this treatment).