Reestablishment of Stenogonum Nutt. (Polygonaceae)

The genus Stenogonum Nutt. (Polygonaceae) is reestablished and distinguished from Eriogonum Michx. with which it has been synonymized since 1853. The genus, as outlined here, differs from Eriogonum in having two whorls of three foliaceous bracts surrounding the flowers instead of the normal, united tubular involucre. Stenogonum contains two species, S. flexum and S. salsuginosum; they are restricted primarily to the Colorado Plateau of Wyoming southward through eastern Utah and western Colorado to northwestern New Mexico and adjacent northern Arizona. Both species are illustrated and their respective ranges mapped.