Dryad

A dryad (or wood nymph) is a female spirit often associated with a location or land form.

Description
In Greek mythology a dryad, or wood nymph, is usally a female spirit typically associated with a particular location or land form. Other nymphs, always in the shape of young maidens, were part of the retinue of a god, such as Dionysus, Hermes, or Pan, or a goddess, generally Artemis. Nymphs, were the frequent target of satyrs. They live in groves, in trees and in valleys and cool grottoes. 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 dryad are connected with that of a tree, the longer the tree lives, the longer would be the life the dryad and if the tree dies, so does she. If this is caused by a mortal the gods will punish him/her. The dryad will them self punish any foolish mortal who tried to hurt their tree. The nymphs at Camp Half-Blood act as waitresses at mealtimes.

They are beautiful humanoids with elf-like appearance and can sometimes be seen with tree-like appendages and sometimes be green.

The Lightning Thief
Luke summons a pit scorpion to kill Percy. When it gets Percy, Percy tries to get back to camp, but he is dying. Luckily, some wood nymphs carry him to the Big House. They are unnamed, but they did save his life.

The Titan's Curse
Grover and Percy watch a satyr chase a redheaded nymph until she goes into tree form and the satyr kisses her. Grover sees this as perfectly normal.

Known Dryads

 * Juniper - Grover's girlfriend, is a wood nymph, and lives in a Juniper tree. Grover is said to once have had a crush on a wood nymph that lived inside a Blueberry Bush.

Trivia

 * In the series, dryads are nymphs of individual trees, while in Greek mythology, a dryad was said to be the nymph of an entire forest or grove of trees. Hamadryads were the nymps of individual trees, and it was said that they rarely left their tree for any reason.
 * Other nymphs related to the earth and woods are:
 * Anthousai: flower nymphs and a type of Oceanid
 * Epimelides: nymphs of highland pasture, the protectors of sheep-flocks. They were perhaps numbered amongst the Oceanids as well.
 * Meliae: nymphs of honey, bees, beekeeping. They were also dryads of the mountain ash.
 * Oreads: nymphs of the mountains