A new species of Parthenocissus (Vitaceae) from India with notes on Causonis trifolia

A new species of Parthenocissus, P. wallichianus is described and illustrated from Kerala, India. This taxon was found and collected previously from India but misunderstood by earlier Indian botanists for names under various combinations among the such as Vitis, Cissus, Cayratia, and Causonis. The combinations were based either on the Linnaean Vitis trifolia or on Lamarck's Cissus carnosa. Both these names are currently accepted as conspecific and validated now as belonging to Causonis trifolia (L.) Mabb.et J. Wen. The new taxon has separated from all these genera by a suit of characters and is shown fit best to the genus Parthenocissus. A key for the identification of Indian species of Parthenocissus is also provided