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 <i>Pyramidanthe</i> (formerly <i>Mitrella</i>), recognizing a total of seven species. Four are described as new, <i>P. montana</i>, <i>P. nervosa</i>, <i>P. oblongifolia</i>, and <i>P. parvifolia</i>, whereas another, <i>P. silvatica</i>, is synonymized under <i>P. schlechteri</i>. Two additional Uvarieae genera, <i>Desmos</i> and <i>Fissistigma</i>, are recorded in New Guinea for the first time. <i>Desmos</i> is reported with the description of a new species, <i>D. insolens</i>, based on a single fruiting collection from the Ramu basin of Papua New Guinea. <i>Fissistigma</i>, sister to <i>Pyramidanthe</i>, is reported following the discovery of two collections of <i>F. latifolium</i> 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 <i>Pyramidanthe</i> 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.