The status of Urocarpidium (Malvaceae): Insight from nuclear and plastid-based phylogenies

An evaluation of the taxonomic status and phylogenetic position of the monotypic genus Urocarpidium Ulbr. (Malvaceae) was undertaken using DNA sequence data. Nuclear (ITS 1 and 2) and plastid (ndhF, rpl16 intron, 3' matK-trnK intron) sequence data were used to reconstruct independent phylogenies for related genera of tribe Malveae, to which Urocarpidium belongs. The nuclear and plastid phylogenies indicate that Urocarpidium albiflorum is not synonymous with Tarasa operculata as previously suggested, consistent with earlier phylogenetic studies. Instead, this species is more closely related to Fuertesimalva and Palaua, although its position relative to these two genera differs in the nuclear and plastid trees. Given the unresolved phylogenetic position and unique suite of morphological characters, Urocarpidium is maintained as a monotypic genus. Full synonymy for Urocarpidium albiflorum is also provided.