Authors: Mora-Pinto, Martha Marcella
Publication: Dissertation, University of Alabama
Year: 2014
Genera: Centrosolenia, Paradrymonia, Trichodrymonia

It is widely known that loss of biological diversity at different levels, such as genetic lineages, species, populations, communities and natural habitats, is imminent in many areas on earth. That loss is exacerbated by the lack of taxonomic knowledge of many groups of organisms. Taxonomic knowledge is necessary to understand the ecology, biogeography and evolutionary history of organisms, as well to accurately implement management plans for the conservation of biodiversity. As with many other neotropical plant genera, Paradrymonia Hanst. (Gesneriaceae) was in need of a taxonomic revision. The genus as traditionally circumscribed includes a non-monophyletic assemblage of approximately 40 species of terrestrial and facultative epiphytic herbs that inhabit the understory of neotropical forests. The generic circumscription of Paradrymonia has been historically confusing and problematic due to the lack of unique diagnostic morphological characters. Molecular data of nuclear ribosomal and plastid DNA were used to reconstruct species relationships within the genus and closely related genera in subtribe Columneinae. Paradrymonia as traditionally defined is paraphyletic and includes taxa in three different clades. Phylogenetic results supported the re-circumscription of Paradrymonia and the resurrection of two previously recognized genera, Centrosolenia and Trichodrymonia, in order to accommodate the remaining ex-Paradrymonia species. New combinations, synonymies and further nomenclatural recommendations are made. A taxonomic revision of a re-circumscribed Paradrymonia is included. The revision includes a dichotomic key and a description for all the eight species. Furthermore, evolution of nine morphological and ecological characters was ii
accessed using ancestral character reconstructions. Most of the characters for different lineages within the Paradrymonia alliance were homoplastic, suggesting convergent evolution as adaptation to similar ecological conditions and pollinators. Finally, Ecological Niche Modeling is used to assess the influence of Pleistoscene climate in the Last Glacial Maximum (LMG; 21,000 BP) on the current distribution of lowland species. Results are consistent with the existence of Pleistocene forest refugia as “museums” and not as drivers of speciation, which is inconsistent with the Pleistocene Refuge Hypothesis. Finally, descriptions for three species new to science, Paradrymonia apicaudata, P. peltatifolia and Nautilocalyx erytranthus, are provided.

Publication website (if available)