About Vitis labrusca L.
Most Vitis labrusca grape varieties produce red fruit, though there are exceptions: white varieties like Niagara and "pink-skinned" varieties like Catawba bear dark berries high in phenolic compounds that create strongly flavored wines. When Vitis labrusca berries are fully ripe and close to harvest, they detach easily from their pedicel (the berry stem). If you gently squeeze a ripe berry between two fingers, its thick skin will slip off easily, leaving the pulp intact as a single ball. This characteristic trait gives Vitis labrusca the common name "slip skin" grapes. Another trait that helps ampelographers identify Vitis labrusca vines and hybrid varieties descended from this species is the vine's large, thick leaves, which have a hairy underside covered in dense brown or white hairs. Like many other American vine species, Vitis labrusca has natural resistance to many grape diseases, including phylloxera. However, its disease resistance and grafting compatibility are not as high as those of other American Vitis species, such as Vitis aestivalis, Vitis rupestris, and Vitis berlandieri. For this reason, Vitis labrusca is not often used for commercial rootstock. Vitis labrusca is a robust plant, and it can be considered weedy or invasive in many US states.
