KANNA (Mesembryanthemum expansum and M. tortuosum) is the common name of two species of South African plants. There is strong evidence that one or both were used by the Hottentots of southern Africa as vision inducing narcotics. More than two centuries ago, it was reported that the Hottentots chewed the root of kanna, or channa, keeping the chewed material in the mouth, with these results: "Their animal spirits were awakened, their eyes sparkled and their faces manifested laughter and gaiety. Thousands of delightsome ideas appeared, and a pleasant jollity which enabled them to be amused by simple jests. By taking the substance to excess, they lost consciousness and fell into a terrible delirium."
Since the narcotic use of these two species has not been observed directly, various botanists have suggested that the hallucinogenic kanna may actually have been cannabis or other intoxicating plants, such as several species of Sclerocarya of the cashew family. These two species of Mesembryanthemum do hove the common name kanna, however, and they also contain alkaloids that have sedative, cocaine-like properties capable of producing torpor in man.
In the drier parts of South Africa, there are altogether 1,000 species of Mesembryanthemum - many, like the ice plant, of bizarre form. About two dozen species, including the two described here, are considered by some botanists to represent a separate genus, Sceletium. All belong to the carpetweed family, Aizoaceae, mainly South African, and are believed to be related to the pokeweed, pink, and cactus families.