The largest subfamily of orchids, Epidendroideae, represents one of the most significant diversifications among flowering plants in terms of pollination strategy, vegetative adaptation and number of species. Although many groups in the subfamily have been resolved, significant relationships in the tree remain unclear, limiting conclusions about diversification and creating uncertainty in the classification. This study brings together DNA sequences from nuclear, plastid and mitochrondrial genomes in order to clarify relationships, to test associations of key characters with diversification and to improve the classification.
All tested characters show significant association with speciation in Epidendroideae, suggesting that no single character accounts for the success of this group. Rather, it appears that a succession of key features appeared that have contributed to diversification, sometimes in parallel.
J.V. Freudenstein and M.W. Chase (2015) Phylogenetic relationships in Epidendroideae (Orchidaceae), one of the great flowering plant radiations. Annals of Botany, January 11, 2015 doi: 10.1093/aob/mcu253