Historically, three varieties or subspecies were recognized within Eriastrum eremicum; these were distinguished by characters such as the number of leaf lobes, the length of the corolla, and the corolla symmetry. This study used traditional multivariate analysis along with spatial
and geostatistical analyses of morphometric data to scan for geographic trends in these morphological characters. In addition to the typical form of E. eremicum in the Mojave Desert of California, both multivariate and spatial statistics revealed a distinct group of populations in southwest
Utah, and another group in southern Arizona. These results suggest that there are some geographic clusters of similar plant morphology within this species, and that three subspecies should be recognized. Plants from southwest Utah are here placed in Eriastrum eremicum subsp. zionis
comb. nov., and plants from Arizona are recognized as Eriastrum eremicum subsp. yageri (M. E. Jones) H. L. Mason.