Data from: Molecular phylogeny and taxonomic revision of the genus Diastatea (Campanulaceae: Lobelioideae)

<p><i>Diastatea</i> (Campanulaceae-Lobelioideae) is a genus of small, herbaceous annuals found mostly in Mexico. Differences in the number of recognized species in the historical treatments, and the lack of a phylogeny, suggested that a revision of the genus was necessary. Species boundaries and species level relationships were tested based on a sampling of nearly 50 individuals. Sequences of the chloroplast spacer regions, <i>atpB-rbcL</i> and <i>ndhF-rpl32</i>, as well as the ITS, were generated and then analyzed using maximum likelihood and Bayesian inference methods. The analyses of the combined dataset produced congruent topologies. Two strongly supported clades of <i>Diastatea</i> are newly recognized as subgenera in the taxonomic treatment. <i>Diastatea</i> Scheidw. subg. <i>Diastatea</i> and <b><i>Diastatea </i></b>subg.<b><i> Angustifolia</i> </b>E.P.Johnson and T.J.Ayers can be distinguished morphologically by leaf shape and pubescence, hypanthium shape, and the presence or absence of a gibbous projection on the ventral side of the corolla. A morphological treatment of the genus corroborated by the molecular analysis revealed one new species, <b><i>Diastatea aptera</i> </b>E.P.Johnson &amp; T.J.Ayers, one new subspecies, <b><i>Diastatea tenera</i></b><i> subsp. <b>durangensis</b></i><b> </b>E.P.Johnson &amp; T.J.Ayers, and elevated an existing subspecies, <b><i>Diastatea ciliata</i></b> (McVaugh) E.P.Johnson &amp; T.J.Ayers, to specific rank.</p>