Phylogeny of Phylica
Phylogenetic analysis of Phylica L. (Rhamnaceae) with an emphasis on island species: evidence from plastid trnL-F and nuclear internal transcribed spacer (ribosomal) DNA sequences
James E. Richardson, Frans M. Weitz, Michael F. Fay, Quentin C. B. Cronk, H. Peter Linder, Gail Reeves, Mark W. Chase 2001 Taxon 50: 405–427. https://doi.org/10.2307/1223889
Summary
The relationships of the island species of Phylica and other genera in Phyliceae (Rhamnaceae) were evaluated using sequences for the plastid trnL intron, the trnL-F intergenic spacer and the internal transcribed spacers of nuclear ribosomal DNA. Both regions provided nearly identical phylogenetic patterns, so they were analysed as a combined matrix. The genera Nesiota and Noltea were found to be palaeoendemic species within the context of the tribe. The island species of Phylica formed a monophyletic group together with the widespread mainland species, P. paniculata. The plesiomorphic, generalist morphology of this group contrasts with the derived morphological characteristics of the majority of mainland species. However, the group occupies a derived position in the phylogenetic trees, thus indicating either a reversal or more likely the retention of these primitive traits.
Discussion:
- For Phylica to be monophyletic, either Nesiota should be placed in Phylica, or P. stipularis should be placed in a separate genus: Trichocephalus
- Phylica originated on the African mainland about 2Mya and all the island species (P. arborea, P. polifolia, P. nitida and P. emirnensis) form a strongly supported clade which includes the widespread mainland P. paniculata (a montane, riverine sp).