Periploca nigrescens Wennberg

POWO follows these authorities in synonymising this name:

• Goyder, S., Harris, T., Masinde, S., Meve, U. & Venter, J. (2012). Flora of Tropical East Africa, Apocynaceae(2): 1-530. [Cited as Parquetina nigrescens.]

This name was accepted following an alternative taxonomy by these authorities:

• Aedo, C., Tellería, M.T. & Velayos, M. (eds.) (1999). Bases Documentales para la Flora de Guinea Ecuatorial; Plantas vascularis y hongos: 1-414. CSIC, real jardín Botánico, Madrid. [Cited as Periploca nigrescens.]
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (eds.) (2006). Flore Analytique du Bénin: 1-1034. Backhuys Publishers. [Cited as Periploca nigrescens.]
• Catarino, L., Sampaio Martins, E., Pinto-Basto, M.F. & Diniz, M.A. (2006). Plantas Vasculares e Briófitos da Guiné-Bissau: 1-298. Instituto de investigação científica tropical, Instituto Português de apoio ao desenvolvimento. [Cited as Periploca nigrescens.]
• Figueiredo, E. & Smith, G.F. (2008). Plants of Angola. Strelitzia 22: 1-279. National Botanical Institute, Pretoria. [Cited as Periploca nigrescens.]
• Lejoy, J., Ndjele, M.-B. & Geerinck, D. (2010). Catalogue-flore des plantes vasculaires des districts de Kisangani et de la Tshopo (RD Congo). Taxonomania. Revue de Taxonomie et de Nomenclature Botaniques 30: 1-307. [Cited as Periploca nigrescens.]
• Sosef, M.S.M. & al. (2006). Check-list des plantes vasculaires du Gabon. Scripta Botanica Belgica 35: 1-438. [Cited as Periploca nigrescens.]