Kanna (Sceletium tortuosum) is a succulent plant native to South Africa. Kanna is also often referred to as channa. A medicine made from kanna called Zembrin is also available. Kanna is used in traditional medicine as a treatment for both stress and depression, which suggests that it contains phytochemicals that affect the central nervous system. A fermented form of kanna called kougoed is also produced and used medicinally for this reason.