Riverbank grape is a vine climbing to 75 feet by means of tendrils.
Leaves are alternate, simple, 4–6 inches long, 3½–5 inches wide, egg-shaped to round, with two short side lobes that are pointed; leaf base rounded with a broad sinus (cleft between two lobes); margins coarsely toothed, lined with fine hairs; upper surface yellowish green, smooth; lower surface paler, hairy on the veins and in the vein axils.
Stems are smooth, slightly ridged; green, gray, or brown; tendrils are opposite leaves. On trunk, bark is reddish brown, shredding in thin strips.
Flowering is in May–June. Flowers are yellowish green, minute, numerous; male and female flowers in separate clusters on same plant; petals 5, dropping early. Clusters 1½–5 inches long, opposite a leaf on new stem growth.
Fruit matures in July–September. Fruit berries, purple to blue with a white, waxy coating, about ⅜ inch thick, sweet, edible, in drooping clusters 2–5 inches long. Stalks hairy.
Similar species: In the past, this species has been separated into three varieties, based on varying degrees of hairiness of leaves and leaf stalks. Most botanists now view this as simply a range of diversity within a single species.
Missouri has eight species of grapes (Vitis) that are either native or naturalized. Also, raccoon grape, peppervine, marine vine, woodbine, and Virginia creeper are less closely related but are in the same family (Vitaceae).
Stems can reach 65 feet or more in length.
Scattered in eastern Missouri, becoming uncommon farther south, and absent from most of the Ozarks.
Habitat and Conservation
Occurs in bottomland forests, mesic upland forests, bases and ledges of bluffs, edges of bottomland prairies, and banks of streams and rivers; also fencerows and roadsides.
People often gather the vines of this and other grape species and use them for making wreaths and other crafts.
This is one of the native grape species that was used extensively in rescuing European wine grape varieties in the late 1800s, after a New World root louse was accidentally imported to Europe. This aphidlike insect pest ravaged European vineyards, threatening to destroy the wine industry centered on Cabernet, Zinfandel, Riesling, Chardonnay, and many other famous varieties; fortunately, people figured out that New World grapes were naturally resistant to the pest, so Old World vines were grafted onto New World rootstocks. Riverbank grape was one of the species that rescued the European wine industry.
The fruit is eaten by many species of birds and mammals, including catbird, cardinal, bobwhite, ruffed grouse, wild turkey, raccoon, red fox, and deer.
The foliage is browsed by deer, and the tendrils are eaten by wild turkey.
The catbird, mockingbird, brown thrasher, and cardinal use the long strips of bark in the middle layer of their nests.
Several species of sphinx moths use grape-family species as larval food plants.