Miswak

Salvadora persica (arak, jhak, pīlu, Salvadora indica, toothbrush tree, mustard tree), is a species of Salvadora. Used for centuries as a natural toothbrush, its fibrous branches have been mentioned by the World Health Organization for oral hygiene use Salvadora persica is a small tree or shrub with a crooked trunk, typically 6–7 metres (20–23 ft) in height. Its bark is scabrous and cracked, whitish with pendulous extremities. The root bark of the tree is similar in colour to sand, and the inner surfaces are an even lighter shade of brown. It has a pleasant fragrance, of cress or mustard, as well as a warm and pungent taste. The leaves break with a fine crisp crackle when trodden on. The tree produces small red edible fruits, juicy but pungent, in clusters.