Phylogenetics and historical biogeography of Encyclia (Laeliinae: Orchidaceae) with an emphasis on the E. adenocarpos complex, a new species, and a preliminary species list for the genus

We explore the phylogenetic position of the Encyclia adenocarpos complex through a multilocus analysis of Encyclia with the following DNA regions: ITS and plastid rpl32-trnL , trnL-F , and ycf1 , analyzed under the Bayesian inference and Maximum Parsimony paradigms. We also performed an analysis of reconstruction of ancestral areas, with particular interest in the first diverging lineages of Encyclia . We used an ad hoc regionalization system designed to fit our distributional Encyclia data to reconstruct the ancestral distribution of the genus and the most relevant nodes. The analyses yielded a moderately well-supported topology with the broadest taxonomic Encyclia sampling yet. Our results indicate the Encyclia adenocarpos complex is monophyletic, highly supported, and sister to a large clade with ca. 95% of the species of Encyclia included in the analyses and suggest the clade is composed of several related, fundamentally allopatric species distributed along the Pacific slopes of Megamexico, including a novelty here proposed, Encyclia mariaeugeniae , which is closely related to Encyclia enriquearcilae yet differing in several diagnostic characters, such as a narrower central lobe to the labellum. The novelty was assessed as EN under IUCN criteria. We provide a key to the E. adenocarpos clade. Our Encyclia phylogeny identifies several clades displaying strong geographic signal; some of these are discussed in terms of morphology, ecological preferences, and pollination syndromes. The reconstruction of ancestral areas indicates with high probability that the earliest diverging nodes of Encyclia occurred in Megamexico. Floral variation within clades suggests the genus colonized geographical areas and underwent diversifications to occupy novel pollination syndromes in a pattern of allopatric, similar assemblages of syndromes composed of unrelated taxa. We present a preliminary species list of Encyclia and their distributions along the major biogeographic areas to provide a hypothesis of diversity patterns and the biogeographical areas where the species occur. As we currently understand the genus, Encyclia consists of 213 taxa, including 179 formally proposed species, 10 undescribed ones, and 25 nothotaxa. We provide five plates depicting 100 species to document the morphological and geographical diversity of Encyclia .