There are eight species, all are found at the Cape region of South Africa. Sceletium Tortuosum (Canna, Kougoed) is the best known and most widely distributed.

The use of Sceletium tortuosum as a mood-altering substance dates back from 1662 to 1685. It was used by pastoralists and hunter-gatherers to decrease thirst and hunger. A traditional method was used to prepare the plant. It was then chewed, smoked or powdered to be inhaled as a snuff. The plant is used to this day as a sedative in the form of tea, decoction or a tincture, and it is used effectively by indigenous healers to wean alcoholics off alcohol. Sceletium tortuosum is not hallucinogenic; it can cause euphoria, initially with stimulation and later with sedation.

Very few people experience severe side-effects. Occasional nausea, an increase in anxiety or irritability and insomnia has been recorded. People taking psychiatric drugs or any cardiac medications are advised not to take Sceletium products. Safety in pregnancy has not been established.