In Greek mythology, the dryads are female spirits of nature (nymphs), who preside over the groves and forests. Each one is born with a certain tree over which she watches. A dryad either lives in a tree, in which case she is called a hamadryad, or close to it. The lives of the dryads are connected with that of the trees; should the tree perish, then she dies with it. The dryads themselves will also punish any thoughtless mortal who would somehow injure the trees.