Synopsis of Nekemias Raf., a segregate genus from Ampelopsis Michx. (Vitaceae) disjunct between eastern/southeastern Asia and eastern North America, with ten new combinations

The genus Nekemias (Vitaceae) was first recognized by Rafinesque in 1838. It has been treated as a synonym of Ampelopsis Michx. Recent phylogenetic studies suggest that Ampelopsis as traditionally delimited is paraphyletic. To maintain the monophyly of each of the genera of Vitaceae, we herein segregate the Ampelopsissect.Leeaceifoliae lineage from Ampelopsis and recognize these taxa in Nekemias Raf., which has a disjunct distribution in eastern to southeastern Asia and eastern North America. Nomenclatural changes are made for nine species and one variety: Nekemiasarborea (L.) J. Wen & Boggan, Nekemiascantoniensis (Hook. & Arn.) J. Wen & Z.L. Nie, Nekemiascelebica (Suess.) J. Wen & Boggan, Nekemiaschaffanjonii (H. Lév. & Van.) J. Wen & Z.L. Nie, Nekemiasgongshanensis (C.L. Li) J. Wen & Z.L. Nie, Nekemiasgrossedentata (Hand.-Mazz.) J. Wen & Z.L. Nie, Nekemiashypoglauca (Hance) J. Wen & Z.L. Nie, Nekemiasmegalophylla (Diels & Gilg) J. Wen & Z.L. Nie, Nekemiasmegalophyllavar.jiangxiensis (W.T. Wang) J. Wen & Z.L. Nie, and Nekemiasrubifolia (Wall.) J. Wen & Z.L. Nie. A taxonomic key is provided for the genus to facilitate identification.