Tarantulas in the south-central US region were historically included in one far-ranging species, Aphonopelma hentzi. Two subsequent studies, however, have split this original taxon into about ten new species. Unfortunately the majority of these putative species were named from only one or two specimens, with variability not taken into account. In order to reevaluate the taxonomic status of the A. hentzi and its peripheral species, we have examined over 100 specimens collected from a wide geographic area including the historical hentzi range. We utilized both molecular and morphological data for this study to give a more robust analysis of the hentzi tarantulas and the peripheral species. We focused on the mitochondrial DNA marker cytochrome oxidase I, where we found only a few or no polymorphisms among individuals in the historical hentzi distribution; in contrast, tarantulas outside of this range showed exceptionally high variation. The molecular data are used to develop a phylogeny of the tarantulas, which supports the hypothesis that the south-central Aphonopelma species should be consolidated. In addition, we found that variations in morphology of the specimens coincide with patterns of variation in the molecular data. We have found there is not adequate divergence for the historical Aphonopelma hentzi group of tarantulas to be considered ten separate species as it is presently.