Revised infrafamilial classification of Symplocaceae based on phylogenetic data from DNA sequences and morphology

Abstract

AbstractPhylogenetic analyses were conducted with 51 parsimony‐informative morphological characters and previously generated DNA sequence data from five genic regions (ITS, trnL‐trnF, rpl16, matK, trnC‐trnD) to revise the classification of Symplocaceae in accordance with ranked monophyly. Observed conflict between the morphological and molecular estimates is interpreted as a consequence of convergent features of the androecium among two clades of the family, possibly influenced by the advent of hummingbird pollination in the largest New World lineage. All nine taxa above the species level in the revised classification (two genera, and within Symplocos two subgenera, three sections, and two series) are based on clades with ≥ 90% bootstrap support values and Bayesian posterior probabilities of 1.00 in molecular analyses. Symplocos section Cordyloblaste (two species) is elevated to the genus level on the basis of both its position as sister to all other Symplocos species and morphological differences that have been used to delineate genera in other Ericalean families. Optimization of the morphological characters onto one of the trees from the combined morphological and molecular analysis suggests that all nine recognized taxa correspond to clades that have at least two morphological synapomorphies, although for two of these clades support is provided by only ambiguous characters. All 318 species of Symplocos, as currently recognized in the literature, are assigned to subdivisions. The assignment of 90 of these is based on molecular and morphological data, and that of the rest (as yet unsampled for DNA sequence characters) on morphological attributes alone. The ranks of two taxa are changed (to Symplocos subgenus Palura and Symplocos series Urbaniocharis), several lectotypes are designated, and a key to genera and subdivisions of Symplocos, descriptions, and complete synonymy are provided.