Plants are an interesting thing. Care for a fact?

Tomatoes and Potatoes have an interesting relation.

Both are members of the nightshade family (which also includes peppers, eggplants, tomatillos, tamarillos and even tobacco)

On a potato plant, they grow little tomato like fruits. Don't eat them though, they're poisonous.
Sweet potatoes are morning glories, not nightshades. So that makes potatoes more closely related to tomatoes than sweet potatoes.