An overview of the nomenclatural types of Orchidaceae names described for Maranhão, Brazil

Maranhão is located within a transitional zone between the Amazon, Cerrado, and Caatinga biomes and harbors a rich flora resulting from the convergence of these major phytogeographic domains. Despite its high biodiversity, the orchid flora of the state has historically received limited taxonomic attention. The first orchid species from Maranhão was described only in 1992, and the first survey devoted exclusively to the state’s Orchidaceae was published in 1999. To date, only ten orchid species have been described from Maranhão, and the holotypes of some of these names are currently considered lost. This study presents a nomenclatural review of all Orchidaceae names described from Maranhão, Brazil. Ten names are treated, including eight in Catasetum, one in Habenaria, and one in Mormodes. Original protologues, type material, and relevant nomenclatural literature were critically examined in accordance with the International Code of Nomenclature for algae, fungi, and plants (ICN). Lectotypes are designated for Catasetum carolinianum and C. maranhense, and nomenclatural notes are provided for all names when necessary. This review clarifies the typification and application of orchid names associated with Maranhão and contributes to the nomenclatural stability of the state’s Orchidaceae.