immortal — not mortal; not liable or subject to death; undying: our immortal souls.
perennial — lasting for an indefinitely long time; enduring: her perennial beauty.
classic — A classic example of a thing or situation has all the features which you expect such a thing or situation to have.
timeless — without beginning or end; eternal; everlasting.
ageless — If you describe someone as ageless, you mean that they never seem to look any older.
noun evergreen
conifer — Conifers are a group of trees and shrubs, for example pine trees and fir trees, that grow in cooler areas of the world. They have fruit called cones, and very thin leaves called needles which they do not normally lose in winter.
fir — any coniferous tree belonging to the genus Abies, of the pine family, characterized by its pyramidal style of growth, flat needles, and erect cones.
hedge — a row of bushes or small trees planted close together, especially when forming a fence or boundary; hedgerow: small fields separated by hedges.
