Plant Atlas of Arizona (PAPAZ)
NPS - Intermountain
USFWS - Region 2
New Mexico Flores
Plant Atlas Project of Arizona (PAPAZ)
Southwest Colorado Wildflowers
Vascular Plants of the Gila Wilderness
Consortium of Midwest Herbaria
Consortium of Southern Rocky Mountain Herbaria
Intermountain Region Herbaria Network (IRHN)
North American Network of Small Herbaria (NANSH)
Northern Great Plains Herbaria
Red de Herbarios del Noroeste de México (northern Mexico)
SERNEC - Southeastern USA
Texas Oklahoma Regional Consortium of Herbaria (TORCH)
CCH2 User Guide
Noel H. Holmgren in Flora of North America (vol. 4)
dioecious or monoecious, spinescent; herbage scurfy-puberulent when young, mostly with branched hairs, becoming glabrate.
erect, much branched, woody throughout, not jointed, forming a rounded bush; younger branches ribbed, rigid; lateral branches becoming spinescent.
alternate, succulent or coriaceous; blade with midveins prominent, spatulate to oblanceolate, sometimes narrowly so, base gradually tapering to petiole, margins entire, apex rounded to obtuse.
terminal, spikelike clusters.
unisexual; staminate in 2-5-flowered clusters in bract axils, perianth 4(-5)-parted, equaling or slightly longer than stamens, stamens 4-5; pistillate in 1
few-flowered clusters per glomerule, each closely invested by 2 wholly united bracts, perianth absent; stigma 2-lobed.
bracts forming flattened, samaralike fruiting structure around utricle, margins thickened, spongy within; pericarp free.
vertical, compressed-lenticular, seed coat brown, tuberculate; embryo annular; perisperm copious.
Encyclopedia of Life
Flora of North America
International Plant Names Index
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Global Biotic Interactions (GloBI)
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