Systematics and biogeography of Oleaceae subtribe Schreberinae, with recircumscription and revision of the Malagasy members.

This article focuses on clarifying the taxonomy, phylogeny, and biogeography of the Oleaceae subtribe Schreberinae, which includes the genera Schrebera and Comoranthus. Using extensive phylogenomic data and morphological analyses, the study reveals that Schrebera is paraphyletic with respect to Comoranthus, leading to the synonymization of Comoranthus under Schrebera, now comprising 16 species distributed across South America, Asia, Africa, Madagascar, and the Comoro Islands. The diversification of Schrebera began in the Early Oligocene (~34 million years ago), with its current disjunct distribution best explained by dispersal events rather than continental vicariance. Madagascar is identified as the center of diversity, harboring ten endemic species, and a detailed taxonomic revision of Malagasy Schrebera, including new species descriptions and conservation assessments, is provided.