A dryad is a tree nymph, that is a female spirit of a tree, in Greek mythology. In Greek drys signifies "oak". Thus dryads are specifically the nymphs of oak trees, though the term has come to be used for all tree nymphs in general. They were normally considered to be very shy creatures, except around the goddess Artemis, who was known to be a friend to most nymphs.
John William Waterhouse (1849-1917) English Pre-Raphaelite painter. Oil on canvas Plymouth Art Gallery, England: artuk.org/discover/artworks/hamadryad-148214/view_as/grid... Hamadryads are tree nymphs of Greek mythology