Revis. Gen. Pl. 2: 545. 1891.
Shrubs, glabrous. Stems erect or decumbent, much-branched, not armed, succulent; branches articulated into small joints. Leaves alternate, ascending, sessile, reduced to scales; blade broadly triangular, base clasping, margins entire, apex acute. Inflorescences terminal spikes, flowers spirally arranged in 3s or 5s in axils of deciduous, peltate, fleshy bracts. Flowers bisexual, sessile; perianth 4–5-lobed, angled, truncate distally, unchanged in fruit; stamens 1–2, exserted; stigmas 2(–3), usually distinct. Fruits utricles, ovoid, compressed; pericarp free, membranous. Seeds erect, brown or reddish brown, oblong, smooth; embryo partly enclosing copious perisperm, radicle inferior. x = 9.
North America, Mexico, Central America, South America.
Species 3 (1 in the flora).