A Systematic Revision of Bakeridesia Hochr. (Malvaceae)
Bakeridesia is a neotropical genus of tall shrubs and small trees, with a center of diversity in the endangered seasonally dry tropical forests of Mexico and Central America. The genus traditionally included two subgenera, one that was primarily Mesoamerican (subg. Bakeridesia) and one that was exclusively Brazilian (subg. Dipteron), but there has been disagreement amongst taxonomists about whether subg. Dipteron truly belongs in Bakeridesia. Bakeridesia as a whole has never been treated taxonomically, but subg. Bakeridesia was the subject of a taxonomic revision by D. M. Bates in 1973. In the nearly 40 years since Bates's treatment, hundreds more specimens of Bakeridesia have been collected and rapid advances have been made in systematics research techniques. In the process of preparing the first modern taxonomic treatment of Bakeridesia, several approaches were used to investigate its species boundaries and phylogenetic relationships. First, phylogenetic analyses of Internal Transcribed Spacer (ITS) sequences provided strong evidence that Bakeridesia is polyphyletic if circumscribed to include the Brazilian subgenus Dipteron. Consequently, the clade comprising subg. Dipteron and several species previously included in Abutilon was removed from Bakeridesia and given the genus name Callianthe. Second, phenetic analyses of morphological data were employed to help determine species boundaries in the taxonomically difficult Bakeridesia integerrima complex; as a result, six new, morphologically cohesive species were described. Finally, field study of natural populations in Mexico complemented examination of herbarium specimens from a broader geographic area to help characterize morphological variation and infer species boundaries in the genus. As a result of these studies, Bakeridesia as currently delimited is a monophyletic genus that includes 22 species, compared to the 13 species recognized in the previous taxonomic treatment.
Biology, Botany, Plant Biology, Systematic, Malvaceae, Malveae, plant systematics, Bakeridesia, Callianthe, Abutilon
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