Taxonomy of Vincetoxicum s.str. (Asclepiadoideae, Apocynaceae) from southern Asia including three new species and resurrected names Sayed Afzal Shah 1,2 , Amir Sultan 3 , Jun Wen 4 , Zahid Ullah 5 , Surat Un Nisa 1 , Zhumei Ren 6 , Muhammad Maqsood Alam 1 , Javed Iqbal 5 , Abdul Samad Mumtaz 1 1 Department of Plant Sciences, Quaid-i-Azam University, Nurpur Road, Islamabad 45320, Pakistan 2 De- partment of Biological Sciences, National University of Medical Sciences, Te Mall, Abid Majeed Road, Rawal- pindi, Punjab 46000, Pakistan 3 National Herbarium, National Agriculture Research Centre (NARC), Park Road, Islamabad, Pakistan 4 Department of Botany, National Museum of Natural History, MRC-166, Smith- sonian Institution, Washington DC 20013-7012, USA 5 Center for Plant Sciences and Biodiversity, University of Swat, Kanju Township, Swat, Pakistan 6 School of Life Science, Shanxi University, Taiyuan, Shanxi, China Corresponding authors: Abdul Samad Mumtaz (asmumtaz@qau.edu.pk), Sayed Afzal Shah (afzaltaxonomist@gmail.com) Academic editor: P. De Block  |  Received 29 December 2020  |  Accepted 20 May 2021  |  Published 17 June 2021 Citation: Shah SA, Sultan A, Wen J, Ullah Z, Un Nisa S, Ren Z, Alam MM, Iqbal J, Mumtaz AS (2021) Taxonomy of Vincetoxicum s.str. (Asclepiadoideae, Apocynaceae) from southern Asia including three new species and resurrected names. PhytoKeys 179: 35–73. https://doi.org/10.3897/phytokeys.179.62514 Abstract Tis paper presents a taxonomic study of genus Vincetoxicum s.str. from southern Asia. Eleven regional endemic species are recognized on the basis of herbarium studies and feldwork. Tree new species are described: V. lenifolium sp. nov. (endemic to Pakistan), V. stewartianum sp. nov. (endemic to India), and V. subcanescens sp. nov. (endemic to Pakistan, Kashmir and Tibet). Tree species names, V. cabulicum, V. glaucum and V. kenouriense, previously treated as synonyms of V. glaucum, V. canescens and V. hirundi- naria, respectively, are resurrected. A neotype is designated for the Afghani endemic V. cabulicum. A lecto- type is chosen from the syntypes of V. glaucum. We resolve the long-standing taxonomic problems in three species complexes: V. arnottianum, V. luridum, V. sakesarense, and V. stocksii; V. glaucum, V. canescens and V. cabulicum; and V. hirundinaria and V. kenouriense. Geo-taxonomic distinctions of southern Asian taxa are highlighted by excluding from henceforth the long misrecognized western Eurasian taxa V. canescens and V. hirundinaria. Furthermore, a detailed account of the genus including illustrations of whole plants, leaves and corona, distribution maps, a taxonomic key, morphological descriptions, synonymy, notes, and information on phenology, distribution and habitats is provided. Finally, provisional conservation assess- ments are provided, which indicate that V. cardiostephanum and V. sakesarense are critically endangered. Copyright Sayed Afzal Shah et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. PhytoKeys 179: 35–73 (2021) doi: 10.3897/phytokeys.179.62514 https://phytokeys.pensoft.net RESEARCH ARTICLE Launched to accelerate biodiversity research A peer-reviewed open-access journal