Flora of North America species comparison

In the southern third of Texas, and in adjacent Louisiana, New Mexico, and Mexico, heads of Liatris punctata tend to be more widely spaced than characteristic for the species over the rest of its range. The most distinctive plants are in trans-Pecos Texas (and Mexico), and they occur at higher elevations than those in the more eastern range. Corms usually are elongate or rhizomiform; Gaiser described L. mucronata var. interrupta from a variant with subglobose corms. Intergrades in head congestion also are encountered, even northward into the Texas panhandle, and the variety is not sharply delimited. The populations with widely separated heads probably were ancestral to L. bracteata and L. cymosa, as well as a race (yet unnamed) with piloso-hirsutulous leaves, which occurs on the Edwards Plateau.

(Discussion copyrighted by Flora of North America; reprinted with permission.)