A phylogenetic survey of Myrtaceae in the Greater Antilles with nomenclatural changes for some endemic species

Abstract

AbstractMyrtaceae are a large family of trees and shrubs, including ca. 2500 species within the predominantly Neotropical and taxonomically problematic tribe Myrteae. Nearly 500 species of Myrteae are endemic to the Caribbean Islands Biodiversity Hotspot, but few have been represented in phylogenetic systematic studies to date. The major goals of this survey are to identify the main lineages of Myrteae present in the Greater Antilles and potential clades for further investigation. Specific objectives are to evaluate the monophyly and placement of the following: (1) the three genera of Myrtaceae considered endemic to the Caribbean Islands (Calyptrogenia, Hottea, Mitranthes); (2) Calycolpus and Pseudanamomis sensu Bisse; and (3) Greater Antillean species of Plinia. To accomplish these aims, species of Myrtaceae representing all genera native to the Greater Antilles were sampled from across the region for placement within previously established phylogenetic frameworks for Myrteae and the large genus Eugenia. In total, 160 terminal taxa of Myrtaceae (89 Caribbean Islands endemics) were analyzed for this study. Phylogenetic inference was conducted by maximum parsimony and Bayesian methods on alignments of DNA sequence data from one nuclear (ITS) and three chloroplast (psbA‐trnH, ndhF‐rpl32, trnL‐trnF) regions. Results of both types of analysis were congruent with each other and with the major clades recovered in previous studies, but some conflict was observed between nuclear and chloroplast regions involving congeneric species. Calycorectes (= Hottea) ekmanii from eastern Cuba was found to be closely related to Calycolpus within subtribe Myrtinae. Subtribes Myrciinae, Pliniinae, Pimentinae (Pimenta and Psidium groups) and Eugeniinae contained other Greater Antillean species. Sampled species of Plinia from Cuba emerged within Myrciaria, and Mitranthes was found to be non‐monophyletic. All sampled species of Eugenia endemic to the Caribbean fell within E. sect. Excelsae (including Calycolpus sensu Bisse), E. sect. Racemosae and E. sect. Umbellatae except for E. cycloidea, which was associated with the Old World species of E. sect. Jossinia. Within Eugenia sect. Umbellatae, Caribbean species formed two major clades, designated C1 and C2, containing species of Calyptrogenia and Hottea from southern Hispaniola, a polyphyletic Pseudanamomis sensu Bisse and the Lathberry Clade, a novel group of Eugenia species centered in Puerto Rico and the Virgin Islands. Calyptrogenia and Hottea species from southern Hispaniola are transferred to Eugenia along with Pseudanamomis nipensis, while Mitranthes species are transferred to Myrcia. Two additional combinations are made within Eugenia and Pimenta in accordance with the results, and lectotypes are designated as appropriate.