New chromosome counts on Rubiaceae from Africa and the Western Indian Ocean islands

Abstract

Cytological studies can provide important insights into circumscription and relationships within plant groups. Nevertheless, there is a considerable lack of cytological information, especially for large and complex groups such as the coffee family (Rubiaceae) and for plants from Africa and the Western Indian Ocean islands. In the present study, 110 new chromosome counts are reported, and one identification for a count published on generic level is provided for the area. Altogether cytological data on 98 species and subspecific taxa classified in 57 genera and 22 tribes are presented. These include first counts for 12 genera and 60 species. Based on a review of recent molecular phylogenetic studies, the significance of these results for the systematics of the Rubiaceae is briefly discussed.