The Element Encyclopedia of Witchcraft: The Complete A-Z for the Entire Magical World - Judika Illes 2005
Dryads are ancient Greek female woodland spirits. Attendants of Artemis, they are the guardians of trees, groves, and forests. The dryads live in trees but should not be confused with hamadryads, who are stationary spirits of individual trees that die when a tree is felled. Dryads, on the other hand, move around quite easily. To see them was considered unlucky, although this may be because as vigilant guardian spirits they most frequently made themselves visible when displeased and intent on inflicting disciplinary action. Dryads are appeased and propitiated with offerings of milk, water, wine, oil, and honey.
See BOTANICALS: Trees; DIVINE WITCH: Artemis; HALL OF FAME: Paracelsus.