Systematics of the fleshy-fruited Sonerileae (Melastomataceae)

Abstract

With approximately 1080 species, Sonerileae is the second largest tribe in the Melastomataceae. Approximately 40% of Sonerileae species belong to fleshy-fruited genera (Catanthera, Heteroblemma, Kendrickia, Medinilla, Pachycentria, and Plethiandra). Relatively few species, especially of the fleshy-fruited taxa, have been sampled for phylogenetic study. Consequently, there is huge uncertainty resulting in many unanswered questions about their evolutionary history, including the monophyly of the largest genus, Medinilla. In this study, the phylogeny of the fleshy-fruited Sonerileae was reconstructed using 385 nuclear and 81 plastid protein-coding loci recovered from target capture. Our study revealed that the fleshy fruited Sonerileae are polyphyletic and belong to three lineages. Kendrickia is sister to an Afrotropical endemic clade. Heteroblemma and Catanthera belong to a second clade and are most closely related to some Phyllagathis and Driessenia species. Medinilla forms a third clade, and includes Pachycentria and Plethiandra. Within Medinilla, fifteen clades are identified and characterized. To make Medinilla monophyletic, the genus is redefined to include Pachycentria and Plethiandra. Major lineages identified within Medinilla lay the groundwork for an infrageneric classification system. Areas of the phylogenetic tree with high conflict or weak sampling are identified to aid further studies in the tribe.