Additions to the Costa Rican Myoxanthus (Orchidaceae: Pleurothallidinae)

Abstract

Pleurothallis cerea, a species described based on a specimen collected by Lankester in Costa Rica, and commonly placed under the synonymy of Myoxanthus octomeriae or M. congestus, is here recognized as distinct. The species is easily distinguished by the shape and size of the leaf, as well as various floral details, especially of the lip. A new combination, tentatively suggested by Carl Luer but never published, is required and therefore validated. Additionally, the vegetatively striking Myoxanthus affinis is recorded from Costa Rica for the first time based on two recent collections. The species is variable within its broad distribution from Colombia to Bolivia and, although differences with the original material from Peru are evident, we cannot be sure at this time that ours represents a different species. Both species are described and illustrated based on living plants.