A phylogenetic analysis of the Arecoid Line of palms based on plastid DNA sequence data.

A phylogenetic analysis of the Arecoid Line (sensu Moore) of palms was conducted using 7 kb of coding and noncoding plastid DNA sequence data. Recovered maximum-parsimony and maximum-likelihood phylogenies support monophyly for the Arecoid Line relative to the rest of the family but paraphyly for subfamily Arecoideae and polyphyly for subfamily Ceroxyloideae (sensu Dransfield and Uhl). Tribes Cocoeae, Geonomeae, Hyophorbeae, and Iriarteae and subfamily Phytelephantoideae were identified as monophyletic as were subfamily Phytelephantoideae + Ravenea (tribe Ceroxyleae of Ceroxyloideae), Podococcus (tribe Podococceae of Arecoideae) + Pseudophoenix (tribe Cyclospatheae of Ceroxyloideae), Reinhardtia (tribe Malortieinae) + tribe Cocoeae (both of Arecoideae), and a clade containing all IndoPacific pseudomonomerous genera of tribe Areceae (Arecoideae). A few taxa show spurious resolution with noncoding plastid DNA data but noncoding data are generally congruent with protein-coding data. Biogeographic interpretation suggests a Gondwanan origin for the Arecoid Line with several lineages found on more than one fragment of the former supercontinent and primary diversification in these groups possibly due to continental breakup vicariance. Three groups involving Cocos, Orania, and the IndoPacific clade demonstrate independent dispersals into the IndoPacific region from a Gondwanan origin.