Molecular phylogenetics provides support for the current circumscription of Rodriguezia (Oncidiinae-Orchidaceae) and for a new infrageneric classification of the genus

• Published in: Plant systematics and evolution Vol. 310; no. 6; p. 46
• Main Authors: Pessoa, Edlley, Christenhusz, Maarten J. M.
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.12.2024
• Subjects: branches; Classification; epiphytes; flower morphology; genus; internal transcribed spacers; Morphology; Orchidaceae; Phylogenetics; Phylogeny; Rodriguezia; Sibling species; species; Taxonomic revision; taxonomic revisions
• ISSN: 0378-2697; 1615-6110; 2199-6881
• DOI: 10.1007/s00606-024-01918-x

The twig epiphyte orchid genus Rodriguezia has never been the subject of a full taxonomic revision, but it was previously hypothesized as non-monophyletic based on the distinct morphology and ITS sequences of R. decora, a Brazilian species. Here we tested this hypothesis by including in the sampling not only R. decora, but also R. rigida, another Brazilian species with similar vegetative and floral morphology to R. decora. Our analysis included both nuclear ribosomal internal transcribed spacer (ITS) and two plastid regions (matK and trnL-F). We found R. decora and R. rigida to be sister species, and this clade is sister to the rest of Rodriguezia. Based on the morphological distinctiveness of these two species compared to the rest of genus, we propose here the first infrageneric classification for Rodriguezia, accepting two subgenera. This study also provides, for the first time, strong support for the phylogenetic position of Trizeuxis as sister to Rodriguezia.