Revised typifications of Isochilus pauciflorus Cogn. (Orchidaceae, Laeliinae) and its synonyms

Faced with ambiguities in a previous typification of Isochilus pauciflorus Cogn., we present a revised typification of this name and comment on its synonyms. Our current study reviews the original materials in open databases of the 23 main herbaria that house orchids from A. Duss, A. Cogniaux or H. G. Reichenbach. Among specimens filed as types, a lectotype (BR0000013217891) is recognized and a presumed isotype (NY00059032) is rejected. However, the lectotype material is not sufficient for precise application of the name. Thus, we designate an epitype based on the specimen K000079638 which refers to the heterotypic synonym Ponera punctulata Rchb. f. to support the name I. pauciflorus. Furthermore, the holotype of P. punctulata commonly accepted and used in the literature is said to be in the Reichenbach Orchid Herbarium, at the Natural History Museum in Vienna (Austria). Unfortunately, this unique gathering is no longer extant or is missing there, but a photograph is available. From this picture, we show that this specimen was not original material, so it was not the holotype. We therefore designate a neotype of P. punctulata Rchb. f. supported by the specimen K000079638. In addition, we designate an epitype of Tetragamestus isochiloides Regel (LE00011188), heterotypic synonym of these above taxa. Finally, the type of Hexadesmia dunstervillei Garay, AMES00287200, is demonstrated to be a lectotype, not a holotype.