Leila M. Shultz in Flora of North America (vol. 4)
erect or decumbent, much-branched, not armed, succulent; branches articulated into small joints.
alternate, ascending, sessile, reduced to scales; blade broadly triangular, base clasping, margins entire, apex acute.
terminal spikes, flowers spirally arranged in 3s or 5s in axils of deciduous, peltate, fleshy bracts.
bisexual, sessile; perianth 4-5-lobed , angled, truncate distally, unchanged in fruit; stamens 1-2, exserted; stigmas 2(-3), usually distinct.
utricles, ovoid, compressed; pericarp free, membranous.
erect, brown or reddish brown, oblong, smooth; embryo partly enclosing copious perisperm, radicle inferior.
Species within checklist:
Petrified Forest National Park