Liparis inaudita (Orchidaceae, Malaxidinae), a new species from the Bosque de Protección Alto Mayo, San Martín, Peru

Abstract

Background: During an ongoing inventory of the orchids of the Bosque de Protección Alto Mayo, northern Peru, a population morphologically assignable to Liparis section Decumbentes was found. This is a little-known group restricted to wet montane Andean forests and consists of four species, from which the BPAM populations differs in leaf and labellum morphology.
 Hypotheses: The features of the plants led us to hypothesize that it represents an unknown species, which can be distinguished morphologically from its congeners.
 Taxon: Liparis section Decumbentes , Liparis sp. nov.
 Study site and dates: Peru, department of San Martín, Rioja province, Pardo Miguel Naranjos district, Bosque de Protección Alto Mayo, sector Venceremos.
 Methods: The unknown entity was studied in detail using fresh, pressed, and alcohol-preserved specimens. We also compared it to type specimens, other specimens of Liparis section Decumbentes housed in herbaria in Peru and abroad, and with descriptions from specialized literature.
 Results: A leaf feature and the unique labellum morphology of the unknown entity permit it to be distinguished clearly from all other species of Liparis section Decumbentes .
 Conclusions: The new species shares with L. sessilis the sessile leaf blades and the convex labellum, but differs from it and all other species of the section in its saddle-shaped labellum, which when spread out is narrowly obtrapezoid, with minute basal auricles, laciniate distal margins, and the apex projected into a narrowly triangular lobe.