Wormwood is a plant, usually considered a weed. There are many varieties, the most commonly known of which is artemesia absinthum, the variety used to make absinthe. The plant is extremely bitter and contains thujone with amounts of the chemical varying between varieties. It has a tendency to ward off insects and other plants as well. The clasical use dating back at least to ancient greek times was for the expulsion of worms from one's digestive tract. It also has apparent abortative effects.