A taxonomic revision of Bulbophyllum, sections Adelopetalum, Lepanthanthe, Macrouris, Pelma, Peltopus, and Uncifera (Orchidaceae)

A revision is presented of six sections of the genus Bulbophyllum (Orchidaceae): sect. Adelopetalum (mainly occurring in Australia), sect. Lepanthanthe, sect. Macrouris, sect. Pelma, sect. Peltopus, and sect. Uncifera (all mainly occurring in New Guinea). Together these include 110 species and 9 subspecies. Fortyseven species and 4 subspecies are new; they are either described in this revision or in precursors to this revision. The genus Dactylorhynchus is reduced to Bulbophyllum. Keys to the species, as well as synonymy, descriptions and illustrations of each species are provided. Some aspects of the morphology of the plants are discussed. A cladistic analysis of each revised section is given. A method to select the closest outgroup species from a number of possibilities is developed; this method is applied here to hypothesize the phylogenetic relationships between the sections. A biogeographical analysis of the New Guinean species is attempted but fails, because most species show overlapping ranges. Nevertheless, observed resemblances between species ranges and the outline of land masses which played a role in the geotectonic history of the island allow a conjectural scenario for the evolutionary history of Bulbophyllum in the area.