This section is from the book "Harper's Guide To Wild Flowers", by Caroline A. Creevey. Also available from Amazon: Harper's Guide To Wild Flowers.
Leaves, 3 to 7-lobed, the lobes sharp-pointed, teeth irregular, large and small, with toothed and persistent stipules. Panicle of flowers and fruit more compact than the last. Berries, blue, covered with a bloom, acid even when quite ripe, juicy. A touch of frost sweetens this grape.
River-banks and wet thickets. Maryland, West Virginia, northward.