Assistant Professor Dr Wilawan Promprom and Assistant Professor Dr Wannachai Chatan, researchers from the Department of Biology, Faculty of Science, Mahasarakham University, discovered a new species of Dischidia (Apocynaceae, Asclepiadoideae) from north-eastern Thailand.
Abstract: Dischidia phuphanensis Chatan & Promprom, a new species from north-eastern Thailand, is described and illustrated. The new species is similar to D. tonkinensis Costantin, but is distinguished by the shape of its leaves, the apices of the staminal corona lobes, the colour of the corolla and the absence of a corolline corona. The distinguishing characters of similar species are discussed. A key for the identification of those species in Thailand without pitcher-like leaves is provided.
Dischidia phuphanensis Chatan & Promprom, sp. nov.
Diagnosis: Dischidia phuphanensis is most similar to D. tonkinensis, but the new species differs from the latter in its elliptic or narrowly elliptic or slightly oblanceolate leaves (leaves in D. tonkinensis are ovate to ovate elliptic, rarely obovate), apex of corona lobes obtuse (with tips pointing downward in D. tonkinensis), yellow base of the corolla tube and light yellow or white apices of the lobes (white or orange-yellow corolla tube and lobes in D. tonkinensis) and the absence of a corolline corona (corolline corona present in D. tonkinensis).
Phenology: Flowering in July–September and fruiting in Aug–December.
Distribution: The new species is endemic to Thailand and is known only from the type locality, Phu Pha Yol National Park, Sakon Nakhon Province, north-eastern Thailand.
Ecology: This new species grows in both slightly open and in shaded areas in mixed deciduous forests at an elevation of 300–400 m.
Vernacular name: Thao Rag Noi. (เถารักน้อย)
Etymology: The specific epithet of Dischidia phuphanensis refers to its type locality, the Phuphan mountain range.
Preliminary conservation status: One population of Dischidia phuphanensis was found at the type locality in Phu Pha Yol National Park, Sakon Nakhon Province, northeast Thailand. It is estimated to number fewer than 250 mature individuals. Therefore, it should be considered “Endangered (EN)” according to the IUCN criteria D (IUCN 2017).
Promprom W, Chatan W (2020) A new species of Dischidia (Apocynaceae, Asclepiadoideae) from North-eastern Thailand. PhytoKeys 144: 23–30. https://doi.org/10.3897/phytokeys.144.47977
