Phylogeny of the palm tribe Chamaedoreeae (Arecaceae) based on plastid DNA sequences

This study presents the first phylogenetic analysis of tribe Chamaedoreeae (Arecaceae), using parsimony and Bayesian analyses of plastid DNA sequences (matK, rps16 intron, 3' region of ndhF, and trnD-trnT). The tribe includes more than 115 species, and has a disjunct distribution with four genera in Central and South America and one genus in the Mascarene Islands. While the placement of Chamaedoreeae within Arecaceae has been controversial, the monophyly of this tribe is well supported by plastid DNA sequence data. All genera in Chamaedoreeae are resolved as monophyletic with high support, but relationships among genera are not fully resolved. The placement of Hyophorbe and the monotypic Wendlandiella as sisters to the remaining genera indicates that solitary flowers and dioecy arose at least twice within this tribe, once in Wendlandiella and once in Chamaedorea. Although a low substitution rate of palm plastic, DNA has been widely noted, the results of this study show high resolution at the species level, especially within the largest genus, Chamaedorea, indicating that plastid DNA is useful for the inference of relationships at low taxonomic levels in some groups of palms.