DRYADES (Dryads) and OREIADES (Oreads) were the nymphs of trees, groves, woodlands and mountain forests. They were the spirits of the oaks and pines, poplar and ash, apple and laurel. For those known as Hamadryades, a tree was born with her birth to which her life was tied. While the tree flourished, so did its resident nymph, but when it died she passed away.
There were several types of Dryades associated with particular trees:
The Meliai (Meliae) were nymphs of the ash-trees. They were born when Gaia (Gaea, the Earth) was impregnated by the blood of the castrated Ouranos (Uranus, the Sky). They were wed by the men of the Silver Age–in the time before the first woman was created–and from them mankind was descended.
The Oreiades (Oreads) were nymphs of the mountain conifers. The eldest of these were daughters of the five Daktyloi (Dactyls) and five Hekaterides (Hecaterides). Subsequent generations were descended from these elder Oreiades and their brother Satyroi (Satyrs).
In ancient Greece most of the forests were located on the slopes of the rugged hills and mountains, as the majority of the lowland forest had been cleared for farming. It was therefore natural for the Greeks to think of Dryades as mountain-dwellers.
The Hamadryades (Hamadryads) were the nymphs of oak and poplar trees. They were usually connected with river-side trees and sacred groves.
The Maliades, Meliades or Epimelides were nymphs of apple and other fruit trees and the protectors of sheep. The Greek word melas–from which their name derives–means both apple and sheep.
The Daphnaie were nymphs of the laurel trees, one of a class of rarer tree-specific Dryad. Others included the Nymphai Aigeiroi (of black poplars), Ampeloi (of grape vines), Balanis (of the ilex), Karyai (of the hazel-nut), Kraneiai (of cherry-trees), Moreai (of the mulberry), Pteleai (of elm trees), and Sykei (of fig trees).
Many of these nymphs were associated with a broader domain–Oreiades were nymphs of the mountains, Alseides of the sacred groves, Aulonides of glens, Napaiai of vales.
Picture 1 : The Dryad by Evelyn De Morgan.Picture 2: Dance of the Dryades, FRENCH 16TH CENTURY- PIERRE MILAN AFTER ROSSO FIORENTINO.Source: https://www.theoi.com/Nymphe/Dryades.html