Taxonomic novelties in New Guinea Uvarieae (Annonaceae): Revision of Pyramidanthe and new genus records of Desmos and Fissistigma

The diversity of climbing Annonaceae in New Guinea, the world’s largest tropical island, remains poorly known. Here, we provide a regional taxonomic account for three genera of the Uvarieae tribe, two of which represent new genus records for the island. First, we revise the genus Pyramidanthe (formerly Mitrella), recognizing a total of seven species. Four are described as new, P. montana, P. nervosa, P. oblongifolia, and P. parvifolia, whereas another, P. silvatica, is synonymized under P. schlechteri. Two additional Uvarieae genera, Desmos and Fissistigma, are recorded in New Guinea for the first time. Desmos is reported with the description of a new species, D. insolens, based on a single fruiting collection from the Ramu basin of Papua New Guinea. Fissistigma, sister to Pyramidanthe, is reported following the discovery of two collections of F. latifolium from the Bird’s Head Peninsula of Indonesia. Due to improper typification of the latter species, a neotype is herein designated. A key to the species of Pyramidanthe is provided alongside a key to the six climbing Annonaceae genera in New Guinea. This account raises to 21 the total number of Annonaceae genera present on the island.