Vitis, Linnaeus, 1753

Ardenghi, Nicola M. G., Banfi, Enrico & Galasso, Gabriele, 2015, A taxonomic survey of the genus Vitis L. (Vitaceae) in Italy, part II: the ‘ Euro-American’ hybrids, Phytotaxa 224 (3), pp. 232-246 : 234

Key to species and hybrids of Vitis in Italy

1. Mature leaf blades white or rufescent-floccose to -tomentose or subglabrous on abaxial surface; tendrils or inflorescences consecutive on 2, 3 or more nodes; adaxial leaf surface reticulate-rugose; ripe berries flavor at least partially foxy; exocarp adherence null or scarce; mesocarp mucilaginous ................................................................................... 2 ( V. labrusca and hybrids)

- Mature leaf blades not heavily tomentose on abaxial surface; tendrils or inflorescences consecutive on 2 nodes; adaxial leaf surface usually smooth; berries flavor never foxy; exocarp adherence strong; mesocarp soft, never mucilaginous.....................................3

2. Tendrils or inflorescences always consecutive on 3 or more nodes; leaf blades always white or rufescent-tomentose on abaxial surface; phylloxera galls always absent on leaf blades; hirtellous pubescence absent on vegetative parts; ripe berries flavor exclusively foxy; juice colorless ....................................................................................................................................... V. labrusca

- Tendrils or inflorescences consecutive on 2, 3 or more nodes; leaf blades white or rufescent-tomentose to -floccose or subglabrous on abaxial surface; phylloxera galls usually present on leaf blades; hirtellous pubescence usually present on vegetative parts; ripe berries flavor foxy and astringent; juice dark red......................................................... V. ×novae-angliae ( V. labrusca × V. riparia )