A tree up to 20 ft. high. Branches succulent, spiny, probably leafless, 3 in. or more in diam., 3–5- (usually 4-) angled, with a solid central part 1/2– 3/4 in. thick, glabrous, bright green; angles wing-like, sinuate-toothed. Leaves rudimentary, scale-like. Spines 1–2 lin. long, stout, in pairs 2/3–1 in. apart, diverging, usually with a pair of minute prickles near their base, dark brown, on horny ovate dark brown shields about 1/4 in. long, obtusely pointed below the spines. Flowering-eyes 2–3 lin. above the base of the spines, shortly separated from the shields. Involucres 5–7 together in a dense cluster, on peduncles (branches of subsessile cymes) 1–1 1/2 lin. long, bowl-shaped, about 1/3 in. in diam, glabrous, with 5 glands and 5 broadly cuneate long-fringed lobes; glands subcontiguous, 1 1/2 lin. in their greater diam., reniform or half-circular, entire. Ovary included, shortly pedicellate, glabrous, with a calyx at its base cut into about 7–9 linear or filiform segments 3/4–1 1/2 lin. long, mostly as long as or longer than the ovary; styles 1 1/2 lin. long, free to the base, widely recurved-spreading, rather slender, subcapitate at the apex.