This looks like a muscadine vine. The grape just isn’t ripe yet. When it gets that way eat it right off the vine. Because of it’s tough skin there is an art to eating the muscadine. Walter could probably explain this process better than me. He may even have a video of the entire process. It would be entertaining! Anyway, check out this link from Walter http://www.walterreeves.com/food-gardening/muscadine-sources/ Late this summer or early fall muscadines will look like this http://plants.usda.gov/java/largeImage?imageID=viro3_003_avp.tif and scuppernongs will be greenish white to bronze.

it’s a wild muscadine vine, in the same family as grapes.

Muscadine

If the fruit turns purple in late summer, it is a muscadine. Check it around Sept./Oct. Buck

It is a wild grapevine.

muscadines. You can eat them when they turn purple, but they’re mot very good.