@ARTICLE{TreeBASE2Ref25965, author = {Marielle Babineau and Anne Bruneau}, title = {Phylogeny and Biogeography of the Afro-Madagascan Genera Delonix, Colvillea and Lemuropisum (Leguminosae: Caesalpinioideae)}, year = {2016}, keywords = {Afro-Madagascar disjunction, divergence time analysis, dry forest species, hybridization, low copy nuclear genes, phylogeny.}, doi = {}, url = {http://}, pmid = {}, journal = {Botanical Journal of the Linnaean Society}, volume = {}, number = {}, pages = {}, abstract = {Our understanding of the taxonomic limits and biogeographical evolution of the Afro-Madagascan genus Delonix, and the closely related monospecific Madagascan endemic genera Colvillea and Lemuropisum, have been hampered by unresolved intergeneric and interspecific relationships. Here we reconstruct the phylogeny of the group using nucleotide sequences from ribosomal ITS, four low copy nuclear genes and four plastid regions. We find poorly resolved gene trees typical of closely related species, suggestive of a lack of time for coalescence, but report conflicting phylogenetic placements only for D. brachycarpa and Colvillea racemose. A divergence time analysis based on the concatenated matrix of all nine loci suggests that the ancestral area of the Delonix, Lemuropisum and Colvillea clade was in Madagascar around 24-18 Ma, with subsequent diversification in the South and Southwest of the island. An out-of-Madagascar dispersal to Africa took place during the Miocene most likely by vegetative rafting. Delonix is not monophyletic due to the robustly supported placement of Lemuropisum edule within the Delonix clade, warranting treatment of Lemuropisum as congeneric with Delonix and establishment of the new name combination Delonix edule, in line with the close morphological similarities between these two genera. In contrast, the phylogenetic position of Colvillea racemosa is unstable occurring in the Delonix-Lemuropisum clade in the nuclear gene trees, but sister to this clade in the plastid gene tree; its status as a distinct genus therefore remains questionable, but is here maintained based on a suite of morphological distinctions, pending further insights into the relationships of this elusive genus. } }

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