Combining Angiosperms353 and Sanger data provides support for the reinstatement of the genus Myrianthemum (Melastomataceae)

Abstract

The increasing availability of DNA sequence data, in particular target enrichment data based on the universal Angiosperms353 probe set, but also accumulated Sanger data from previous phylogenetic studies, is facilitating the placement of taxa that are difficult to place with certainty based on morphological evidence alone. Here, we investigate phylogenetic relationships of Medinilla mirabilis (Melastomataceae), a species distributed in central Africa and currently classified in the mega-diverse genus Medinilla of tribe Sonerileae. Medinilla mirabilis is a twining liana with verticillate leaves when young, spherical inflorescences, 4-merous flowers, dimorphic stamens, and baccate fruits. Our results revealed that M. mirabilis is sister to tribe Dissochaeteae and only distantly related to Medinilla. We also provide new data on wood anatomical and seed morphological characters of M. mirabilis. The alternate inter-vessel pits in M. mirabilis and Dissochaeteae are consistent with the phylogenetic placement. Seeds of M. mirabilis are similar to those of Dissochaeteae and of Medinilla. Due to its unique morphology and phylogenetic position, we propose to reinstate the monospecific genus Myrianthemum with Myrianthemum mirabile. This necessitates expansion of the Southeast Asian tribe Dissochaeteae to include Myrianthemum as its only African member. Our study of M. mirabile demonstrates that the combined application of Angiosperms353 and Sanger data is a cost-effective approach to phylogenetically place enigmatic taxa.