A dryad (or wood nymph) is a usually female spirit often associated with a certain tree.
The nymphs at Camp Half-Blood act as waitresses at mealtimes and competitors in running races.
Luke Castellan summons a pit scorpion to kill Percy Jackson. When it stings Percy, he 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.
Meg had a dream in which she came to know where Hercules the cactus hid the seven seeds of the Meliai. She planted them at the ruins of Aeithales. In spite of the hostile environment, the seeds grew into saplings at an unusually fast rate. In two days, the Meliai returned to their prime adult form. They then heard the nature song of Meg and Grover Underwood in the Burning Maze.
Teaming up with Piper, the Meliai attacked the main entrance of the maze. They forced their way through to the place where Grover, Meg, Apollo and Herophile were trapped. Piper killed Medea. Then, they all teamed up and managed to force their way to the nearest exit. Outside the exit, the Meliai killed the powerful Incitatus and all of his pandai guards.
Finally, the Meliai transplanted themselves and put their roots around the pool at the ruins of Aeithales. Their magic worked so well that Aeithales rebuilt itself in a day.
A dryad either lives in a tree or close to it. The life of dryad is connected with that of a tree. That is, the longer the tree lives, the longer the dryad does. The dryad will punish any mortal who tries to hurt its tree. If the death of a dryad is caused by a mortal, the gods will punish him/her.
Dryads are beautiful humanoids with elf-like appearance. They are sometimes be seen with tree-like appendages and are sometimes green.
- Juniper: A female dryad who lives in a Juniper tree at the Camp Half-Blood's woods.
- Prickly Pear
- Aloe Vera
- Joshua: A male dryad who lives in a Cistern near Palm Springs.
- Money Maker
- The Meliai: The seven eldest dryads.
- Poison Oak: A female dryad who lives at Camp Jupiter's woods.
- According to Apollo, male dryads, such as Joshua, are quite rare.
- They can, apparently, absorb fire to protect their forests as they did in The Hidden Oracle. They may posses some control over plant life.
- 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 nymphs of individual trees who rarely left their tree for any reason.
- Many nymphs related to the earth and woods are:
- Aigeroi: Nymphs of black poplars
- Ameploi: Nymphs of grape vines
- Anthousai: Flower nymphs and a type of Oceanid
- Balanis: Acorn and ilex nymphs
- Daphnaie: Laurel nymphs
- Hamadryades: Dryads of oak and poplar trees
- Karyai: Nymphs of hazel-nut trees
- Kraneiai: Nymphs of cherry trees
- Mailiades (Epimelides): Nymphs of apple and other fruit trees, highland pasture; the protectors of sheep. They were perhaps numbered among the Oceanids as well.
- Meliae: Nymphs of honey, bees, beekeeping. They were also dryads of the mountain ash.
- Moreai: Nymphs of mulberry trees
- Orieades: Nymphs of the mountains oaks and pines
- Pteleai: Elm Nymphs
- Sykei: Fig Nymphs
- Anthousai: Flowers