Riverbank Grape

Appearance

Mature vines have loose, fissured bark, and may attain several inches in diameter. Leaves are alternate, often with opposite tendrils or inflorescences, coarsely toothed, 5–25 cm long and 5–20 cm broad, sometimes with sparse hairs on the underside of veins.

"V. riparia" is functionally dioecious. The inflorescence is a panicle 4–15 cm long and loose, and the flowers are small, fragrant, and white or greenish in color. "V. riparia" blooms sometime between April and June and in August or September produces a small 6–15 mm blue-black berry with a bloom, seeded, juicy, edible, vinous in flavor, lacking the "foxy" characteristics of "Vitis labrusca", but usually quite sour and herbaceous. "V. riparia" has a wide range and may deviate considerably in detail from the above general description. White berries, perfect flowers, large clusters, large berries, and sweet fruit are among the known variations. However, some observers consider such variations as evidence of natural hybridization with other species of grapes.

Habitat

"Vitis riparia" has the largest geographical range of any of the North American Vitis species. It is present across nearly the entire eastern half of North America, excepting the far south and the most western portions of the great plains. Variants of the species have been observed as far north as Riding Mountain National Park in Manitoba, Canada and as far west as Montana, Nebraska, and North Dakota.

In the wild, the vine thrives along exposed areas with good sun exposure and adequate soil moisture, such as riverbanks, forest clearings, fence lines and along road sides. The species has adapted to a variety of soil chemistries.

Uses

Perhaps the most significant agricultural usage of "V. riparia" is as grafted rootstock for Vitis vinifera. Important advantages of the use of "V. riparia" include resistance to phylloxera and adaptation to variant soil types.

Due to the extensive cold hardiness and fungal disease resistance of this species, it has been used extensively in grape breeding programs to transfer cold hardy and disease resistant genes to domesticated grapes. The French-American hybrid grapes are notable examples of these attempts. "V. riparia" has been used extensively for over a hundred years to create hardy hybrids. Many "V. riparia" hybrids are currently being used and investigated by plant breeders and in breeding programs such as those conducted by the University of Minnesota's horticulture program in an effort to make a commercially viable wine grape that can survive the northern climate of the Upper Midwest. Examples of commercially important cultivars with significant "V. Riparia" ancestry include Baco noir, Marechal Foch, Triomphe d'Alsace and Frontenac.

While "V. riparia" shares many important characteristics with its cousin, Vitis vinifera, the small size of the berry, the high acidity of its fruit, the intense pigment of its juice, and the presence of herbaceous aromas in wine produced from it have made it unusable on its own for commercial viticulture.

These grapes are sometimes used to make flavorful homemade jellies, jams, and wine.