Bulbophyllum papuaense (Orchidaceae), a new species from Indonesia

Abstract A new species, Bulbophyllum papuaense, was described and illustrated from Indonesia. Bulbophyllum papuaense is similar to Bulbophyllum tortuosum and B. muscohaerens but differs from them by having rhizome and pseudobulbs covered with papillose scales, caudate and ciliate petals, linear and ciliate lip.


Introduction
Bulbophyllum is among the largest genera of angiosperm, composed of more than 2200 species and widely distributed in tropical and subtropical regions throughout Africa, Asia, and the South Americas (Lindley 1830, Pearce and Cribb 2002, Seidenfaden 1979, 1992, Chen and Vermeulen 2009, Gravendeel and Vermeulen 2014, Chase et al. 2015, Govaerts et al. 2019, Vermeulen and O'Byrne 2011. Bulbophyllum is usually characterized by its creeping or pendent rhizomes with 1-internoded pseudobulbs, apex of pseudobulb with one or two non-sheathing leaves, inflorescences arising from nodes the rhizome, lateral sepals and column foot forming mentum, and waxy pollinia (Gravendeel and Vermeulen 2014).
Papua is the largest tropical island in the world and has a rich flora. It is estimated that there are 2869 orchid species in Papua (Ormerod 2017), most of which are endemic in Papua. For example, there are about 647 species in 36 sections of Bulbophyllum in New Guinea, out of which 590 species are endemic (Ormerod 2017). Most of these species are distributed in tropical montane forest (Ormerod 2017). During our fieldwork in montane forest in West Papua, Indonesia, in August 2016, a new species of Bulbophyllum was discovered and is described below. Diagnosis. Bulbophyllum papuaense is close to Bulbophyllum tortuosum and B. muscohaerens but differs from them by having rhizome and pseudobulbs covered with papillose scales, caudate and ciliate petals, linear and ciliate lip which curve at the tip.
Ecology. Bulbophyllum papuaense was discovered in broad-leaved, evergreen montane forest in Mokwan, West Papua. Bulbophyllum papuaense is epiphytic on trunks or shrub in humid and shady areas in montane forest. Plants are tiny and grow usually with moss. Our observation indicated that it was in full bloom in August. Bulbophyllum papuaense is only known from the type locality.
Conservation status. The tropical montane rain forest is well protected in Mokwan region. However, the rain forest is very difficult to reach due to poor transportation. Our  examination in BO and Herbarium of Universitas Papua (Manokwari) did not find other collections of this species. Therefore, this new species is currently considered as DD.
Etymology. The name derives from the Papua, where the new species was discovered. Taxonomic notes. Bulbophyllum papuaense belongs to sect. Oxysepala which is often characterized by 1-flowered inflorescence, lateral sepals connate, basal node of pedicel near at same level with the attachment of floral bract (Vermeulen et al. 2015). Bulbophyllum papuaense is a distinctive species in sect. Oxysepala and easily differs from its relatives by its morphological characters, such as the rhizome with warty scales, caudate and ciliate petals, linear lip recurve and with white hairs.
Key to Bulbophyllum papuaense and its alliance