A Witchwood Tree is a tree added by Ars Magica 2, which is a part of some crafting recipes, and is one of the possible base blocks for a Crafting Altar.
Witchwood Trees spawn across most biomes but are most frequent in forests
Aums are generally found around these trees.
Witchwood saplings do not grow under normal circumstances. In order to grow, they must be planted on a block of dirt or grass that is adjacent to one or more pools of Liquid Etherium. The more Liquid Etherium surrounds the sapling, the more likely it is to grow. When a Witchwood Sapling grows into a Witchwood Tree, it has a chance to spawn Aum flowers on dirt or grass blocks close to it.