How to Identify Muscadine Vines
The clusters of grapes on muscadine vines are smaller in number and more loosely arranged than grape clusters grown in gardens.
Break off or prune a section of vine to bring to a nursery, cooperative extension office or botanical garden to have a horticulturist assist you in proper identification.
If you're not sure the unidentified plant is a muscadine, refrain from tasting the fruits to prevent any possibility of an allergic reaction or mild poisoning.
Muscadines (Vitis rotundifolia), also called scuppernong or bullace, is a species of grape vine native to the American Southeast. A vigorous growing plant, it grows either as a climbing, erect vine up to 90 feet tall; or as a prostrate sprawling groundcover, clambering over low shrubs and small trees. You're most likely to encounter a muscadine in a moist, fertile soil in an open, sunny woodland setting. It tolerates winter cold down to minus 5 degrees Fahrenheit, corresponding to regions rated U.S. Department of Agriculture hardiness zones 6 through 10.
Look at the foliage of the vine. Leaves are a satin, glossy green and shaped like rounded hearts or triangles measuring between 3 and 5 inches in diameter. Unlike other species of grapes, muscadine leaves reveal no lobes but do develop irregular, coarse, blunt teeth or zig-zagging edges on their leaves. In autumn, the leaves turn shades of yellow before dropping off.
Examine the twigs and bark of the plant if no foliage is present, such as in winter. Muscadine vines, according to Duke University and the Lady Bird Johnson Wildflower Center, have a non-peeling, rather smooth bark, whereas other species' are exfoliating (peeling or shredding). Bark color is battleship gray, becoming fawn brown at the youngest growing tips. These thin twigs (also called branchlets) have an angled shaped, not smooth and round, and the dormant buds are small, round and fuzzy red-brown, according to the university.
Search for growing plants from spring through autumn for further clues to its identity. Duke University further states that the tendrils on muscadine grape vines are simple with no forks at the tips. The tiny clusters of flowers occur in mid-spring. Developing grapes are green, eventually ripening to glossy, dark, blackish purple in late summer to earliest autumn (September or October). Once ripe, the fruits tend to quickly drop to the ground.
Taste the ripe fruits. Muscadine grapes embue a musky flavor that is juicy but mildly sweet. Grape skins are thick and leathery, snapping open once squeezed.