Man selling khat, Jebel Bura. Khat is an evergreen plant originally from East Africa. A shrub or small tree growing to 5–8 m tall, with leaves 5–10 cm long and 1–4 cm broad, khat is classified as an illicit substance in most of the world. It is not considered physically addictive, although many chewers claim dependency. The chewer puts khat leaves in his/her mouth and chews them slowly for hours, alternately sucking the liquid out of the khat and sipping a beverage (usually one that is quite sweet, like soda.) The khat is not swallowed.