title: Biogeography of the Malagasy Celastraceae: Multiple independent origins followed by widespread dispersal of genera from Madagascar.
abstract: Of the 97 currently recognized genera of Celastraceae, 19 are native to Madagascar, including six endemics. In this study we conducted the most thorough phylogenetic analysis of Celastraceae yet completed with respect to both character and taxon sampling, and include representatives of five new endemic genera. Fifty-one new accessions, together with 328 previously used accessions of Celastrales, were sampled for morphological characters, two rDNA gene regions, and two plastid gene regions. The endemic Malagasy genera are resolved in two separate lineages-Xenodrys by itself and all other endemic genera in a clade that also includes four lineages inferred to have dispersed from Madagascar: Brexia madagascariensis (Mascarene Islands, coastal Africa), Elaeodendron (West Indies, Africa to New Caledonia), and Pleurostylia (Africa to New Caledonia). Of the 12 extant Malagasy Celastraceae lineages identified, eight are clearly of African origin. The origins of the remaining four lineages are less clear, but reasonable possibilities include America, Eurasia, Africa, southern India, Malesia, and Australia. Based on 95% credible age intervals from fossil-calibrated molecular dating, all 12 extant Malagasy Celastraceae lineages appear to have arisen following dispersal after the separation of Madagascar from other landmasses within the last 70 million years.
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, SE-413 19 Gothenburg, Sweden; Laboratório de Biología Molecular (CINBIN), Department of Biology, Universidad Industrial de Santander, Bucaramanga, Colombia.
authors.forename: Christine D
authors.initials: CD
authors.lastname: Bacon
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO 80523-1878, USA. Electronic address: psimmons@lamar.colostate.edu.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Simmons
authors.affiliation: South African National Biodiversity Institute, National Herbarium, Private Bag X101, Pretoria 0001, South Africa.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Archer
authors.affiliation: College of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
authors.forename: Liang-Cheng
authors.initials: LC
authors.lastname: Zhao
authors.affiliation: Parc Botanique et Zoologique, Rue Fernand KASANGA, Tsimbazaza, Antananarivo 101, Madagascar.
authors.forename: Jacky
authors.initials: J
authors.lastname: Andriantiana
mesh_terms: D000349:Africa; D001315:Australia; D029753:Celastraceae / Q000145:classification* / Q000235:genetics*; D005580:Fossils; D051456:Gene Flow; D007194:India; D008270:Madagascar; D009510:New Caledonia; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal / Q000235:genetics; D018087:Plastids / Q000235:genetics; D017422:Sequence Analysis, DNA; D014900:West Indies
keywords: Brexiella; Evonymopsis; Hartogiopsis; Madagascar flora; Polycardia; Salvadoropsis