Dryad. In Greek mythology a Dryad is a tree nymph, or female tree spirit. Dryads are specifically the nymphs of oak trees, although the term has come to be used for all tree nymphs in general. Each Dryad is born with an individual tree and either lives in the tree over which she watches, or close to it. The life of a Dryad is connected with that of her tree and should the tree perish she dies with it. A Dryad will also punish any mortal who would injure the tree she presides over.