J Syst Evol ›› 2020, Vol. 58 ›› Issue (6): 1090-1107.DOI: 10.1111/jse.12697

• Research Articles • Previous Articles    

Phylogeny and taxonomy of Afrocayratia, a new genus of Vitaceae from continental Africa and Madagascar

Romer Narindra Rabarijaona1,2 , Viet-Cuong Dang3 , Gaurav Parmar1,2 , Bing Liu1,4 , Jun Wen5 , Zhi-Duan Chen1,4 , and Li-Min Lu1 *   

  1. 1 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
    3 Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, Hanoi 10072, Vietnam
    4 Sino‐Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China
    5 Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013‐7012, USA
  • Received:2020-07-25 Accepted:2020-10-07 Online:2020-10-14 Published:2020-11-01


The genus Cayratia Juss. in the traditional sense (i.e., Cayratia s.l.) of the grape family has been shown to be non‐monophyletic. Previous studies supported the splitting of Cayratia s.l. into three genera, that is, Cayratia s.s., Causonis Raf., and a new genus representing the African Cayratia clade. However, the morphology of the African Cayratia clade has not been studied carefully and its phylogenetic position within Vitaceae remains unclear. Our study integrates molecular, distributional, and morphological data and supports the recognition of the new genus Afrocayratia from continental Africa and Madagascar. Phylogenetic analyses strongly support the monophyly of Afrocayratia and resolve it as a sister of Cayratia s.s. based on the chloroplast data, but it is placed sister to Cyphostemma based on the internal transcribed spacer dataset. Molecular dating suggests that Afrocayratia split with Cayratia s.s. during the Paleocene, but that the extant species of Afrocayratia did not diversify until the early Miocene. Afrocayratia differs from its allied genera in having short stigmas and seeds with subcircular ventral infold cavities in cross‐section. Three clades are detected within Afrocayratia, with A. debilis (Baker) J.Wen & L.M.Lu as the first diverged lineage. The second diverged lineage includes A. delicatula (Willems) J.Wen & Z.D.Chen and A. gracilis (Guill. & Perr.) J.Wen & Z.D.Chen. The third diverged lineage includes A. imerinensis (Baker) J.Wen & L.M.Lu, A. longiflora (Desc.) J.Wen & Rabarijaona, and A. triternata (Baker) J.Wen & Rabarijaona from Madagascar, which form a monophyletic group that diverged from the second lineage in the middle Miocene. Combining the morphological and molecular evidence, we formally describe the new genus Afrocayratia, make seven new combinations, and provide a key to species of the genus.

Key words: Afrocayratia, Cayratia, continental Africa, Madagascar, molecular phylogeny, new genus, seed, Vitaceae