Evolutionary Patterns in Apiaceae: Inferences Based on matK Sequence Data

Abstract

Phylogenetic relationships among the genera of Apiaceae are poorly understood, and the commonly employed systems of classification of this family are widely regarded as artificial. The understand- ing of evolutionary relationships in Apiaceae has been hampered by difficulties in interpreting traditional taxonomic characters, especially fruit characters. A cladistic analysis of 53 sequences from the chloroplast gene matK was used to provide a phylogenetic perspective for interpreting evolutionary patterns and relationships in Apiaceae. Results of the analysis of mnatK sequence data are in conflict with the subfamilial and tribal treatment of Cerceau-Larrival, as well as the tribal system of Drude. matK sequence data do support much of Drude's subfamilial system, suggesting subfamilies Apioideae and Saniculoideae are largely monophyletic. The saniculoid genus Lagoecia, however, is found among the apioids and should perhaps be transferred to that subfamily. Three of the apioid genera analyzed (Bupleurum, Anginon, and Heteromorpha) are placed in basally-branching clades within subfamily Apioideae. This topology, along with evidence from morphology, anatomy, geographic distribution, and insertions and deletions in matK sequences, suggests that subfamily Apioideae may have originated in southern Africa from woody, simple-leaved ancestors. Relationships among the remaining taxa of Apioideae agree largely with other recent molecular studies, and suggest that the carpological characters used to construct older systems of classification have been prone to parallel evolution.