Zanthoxylum clava-herculis, Hercules' club, Pepperwood, or Southern prickly ash, is a spiny tree or shrub native to the southeastern United States. It grows to 10–17 m tall and has distinctive spined thick, corky lumps 2–3 cm long on the bark. The leaves are glabrous and leathery, the flowers are dioecious, small with 3-5 white petals. The fruit is a two-valved capsule 6 mm diameter with a rough surface, and containing several small black seeds. It is sometimes called "Toothache tree" or "Tingle tongue" because chewing on the leaves, bark, or twigs causes a tingling numbness of the mouth, tongue, teeth and gums. It was used for such medicinal purposes by both Native Americans and early settlers.