A PRELIMINARY ANALYSIS OF EVOLUTION OF AFRICAN AND MADAGASCAN APIACEAE

Abstract

A broad overview of the current state of taxonomic knowledge on the Apiaceae of Sub-Saharan Africa and Madagascar is presented. Sub-Saharan Africa has about 69 indigenous genera in the family, with 38 of them endemic, while Madagascar has at least 16 genera, of which six are endemic. Many taxa are poorly known and show unusual combinations of character states. Generic delimitations have not yet reached stability but monographic work, in which morphological, anatomical and some chemical characters are rigorously analysed, is contributing steadily to an improved understanding of generic relationships. A preliminary cladistic analysis of some genera is presented, based on characters such as woodiness, leaf persistence, leaf type, dentate-serrate leaf margins, heteromorphous fruits and the co-occurrence of intrajugal and vallecular vittae. Despite poor resolution, the results consistently show that several African and Madagascan genera are basal to the rest of the Apiaceae. The subfamily Saniculoideae Burnett always appears in a basal position, in close association with anomalous genera such as Lichtensteinia Cham. & Schltdl., Polemanniopsis B. L. Burtt, Steganotaenia Hoscht. and Pseudocarum C. Norman. These genera are clearly central to a better understanding of the early evolution of the family and also to an ultimate improvement of Drude's (1898) classification system.