Phylogeny and biogeography of Spathelioideae (Rutaceae)

Appelhans, M.S. (2011)

Doctoral Thesis

This thesis presents a detailed molecular phylogenetic and biogeographic study of the Spathelioideae clade, a group of seven small Sapindalean genera with remarkable morphological diversity. The systematic placement of these genera has always been in dispute and the results of this thesis show that Spathelioideae are a monophyletic sister clade to the Rutaceae family. Except for the South American and Caribbean genus Spathelia, all Spathelioideae genera are monophyletic. The South American species have been transferred to a resurrected genus Sohnreyia accordingly. Molecular dating analyses suggest an origin of Spathelioideae in the Late Cretaceous. Assuming a palaeotropic origin of Rutaceae, the stem lineage of Spathelioideae might have originated in Central western and central Africa. The divergence of a Neotropical and a Palaeotropical lineage of Spathelioideae might be explained by long-distance dispersal during the Late Cretaceous or Palaeocene. Within the Neotropical clade, one dispersal event to the Caribbean occurred possibly via a landbridge or a series of islands. Sea level changes in the Pleistocene have isolated and connected landmasses in the Caribbean and might have been triggers for speciation of the genus Spathelia. Within the Palaeotropic clade, dispersal events from Africa to the Mediterranean & Canary Islands, Madagascar, and South-East Asia occurred.

• Transatlantic distribution
• Spathelia
• Sapindales
• Rutaceae
• Ptaeroxylon
• Plant systematics
• Molecular phylogeny
• Cneorum
• Biogeography

• All authors: Appelhans, M.S.
• Supervisor: Smets, E.F.
• Co-supervisor: Keßler, P.J.A
• Qualification: Doctor (dr.)
• Awarding Institution: Faculty of Science, Leiden University
• Date: 2011-11-15
• ISBN (print): 9789071236761