The ivy is not considered a tree, but depends on a host tree for support. Ivy belongs to the evergreen family, and oversees the month of September. It's leaves are deep green and rather waxy, and it has thin tendrils that attach themselves to surfaces, and are strong enough to force their way into bricks, cracks, and plaster. Ivy can grow in such abundance on a host tree that it smothers the tree and actually kills it.
Ivy berries can be used for medicinal purposes, but can be poisonous if taken In large quantities. A broth of fresh leaves can be used to cleanse sores or wounds. A powder made from dried leaves and berries can be used to clear stuffy heads, and is also believed to be a cure for hangovers.
The Ivy was considered to be a very powerful tree to the Celts because of its ability to kill even the mightiest Oak tree. Because of its tendency to create dense, inpenetrable thickets in the forest, it is seen as more powerful than the vine, and rather sinister in nature.