Ophioglossella (Orchidaceae-Aeridinae), a New Genus from Papua New Guinea

In the highlands of Papua New Guinea an evidently undescribed orchid belonging to subtribe Aeridinae has been found on several occasions in widely scattered localities, but almost always, it seems, in very low numbers. The scarce material in herbaria (four out of the five available collections are unicates) was identified as Sarcochilus, Pteroceras, Dryadorchis or Grosourdya. Two of these genera (Pteroceras and Grosourdya) are not known to occur in New Guinea, and the New Guinea members of Sarcochilus probably constitute a separate genus. The specimens we have seen are rather variable in the size and shape of the leaves, but they agree in the unusually complex morphology of the labellum. Our attempts to find a genus in which this strange orchid could be accommodated failed, and we concluded (at first independently) that it belonged to an as yet undescribed genus. This so far monotypic genus, which we propose to call Ophioglossella, does show similarities with each of the four genera mentioned above. These in turn belong to a larger group of genera within subtribe Aeridinae that are distinguished by having a mobile labellum, hinged with the apex of a distinct column-foot. Most genera in this group are small, distinctive, and unlikely to be confused with Ophioglossella. A key to those genera with which a closer comparison is justified is provided below.