A review of the ecology and natural history of Kalanchoe (Crassulaceae subfam. Kalanchooideae) in southern Africa

Summary: In terms of number of taxa accepted at present – about 180 – Kalanchoe (Crassulaceae subfam. Kalanchooideae) is the third largest genus recognised in the family. Madagascar is home to more than one third of the recognised taxa with the rest spread across Africa, and the Near, Middle, and Far East. In terms of growth form (trees, various types of shrubs, herbs, epiphytes; all leaf succulents), Madagascar also harbours the greatest diversity found in the genus. Several Malagasy species of Kalanchoe have attracted significant research interest from horticultural, (eco-)physiological and invasions biological perspectives. However, the species that occur beyond Madagascar have not been studied to the same degree. This review provides a synthesis of field observations made over several decades, especially in southern Africa, and of available information on several aspects of kalanchoe biology and ecology assembled from a wide range of sources. Such synthesised knowledge is important for, inter alia, informing conservation management strategies for wild kalanchoe populations, as well as more widely for the grassland and savanna and, to a lesser degree, forest and thicket, habitats in which the species mostly occur.