In British ColumbiaHeuchera chlorantha, andH. cylindrica vars.orbicularis,cylindrica, glabella, andseptentrionalis occur in succession from west to east.H. cylindrica var.ovalifolia occurs mainly in eastern Oregon and southern Idaho.H. saxicola occurs mainly in central Idaho, southern Montana and southeastward. Where they meet all the varieties ofH. cylindrica intergrade freely, and some intergradation ofH. cylindrica occurs withH. chlorantha andH. saxicola. On the east slope of the Washington Cascades there are disjunct populations of nearly typicalH. saxicola, H. cylindrica var.cylindrica, H. cylindrica var.glabella, andH. cylindrica var.ovalifolia. These populations suggest the occurrence of Pleistocene refuges separated by valley glaciers in this region.