Traditional uses of the remarkable root bark hairs of Lannea schweinfurthii var. stuhlmannii (Anacardiaceae)by the Vhavenḓa, South Africa

Lannea schweinfurthii var. stuhlmannii, an African tree ranging from Sudan southwards to South Africa, has its thicker roots covered by an unusual furry layer of hair-like structures originating from the periderm. Wool-like hairs harvested from this layer, known in the vernacular Tshivenḓa as vhulivhadza, is a widely used and traded natural product in Limpopo Province, South Africa. Here we provide a detailed account of the cultural uses of vhulivhadza based on original ethnobotanical surveys among the Vhavenḓa, as well as a review of the literature. Our findings indicate that vhulivhadza is a “magical medicine,” mostly used to induce several forms of forgetfulness, both in humans and in animals. Various uses reported for L. schweinfurthii and L. alata, the latter an East African species with similar root bark hairs, suggest that the custom to use these hairs to induce forgetfulness is confined to southern Africa. The practice of taking traditional medicine to “forget something” or “to make people forget” is quite widespread in southern Africa. We discuss vhulivhadza and a few other plants used locally for this purpose, notably the mysterious sho-|õä plant of the now extinct | Xam culture, Asclepias crispa (Apocynaceae: Asclepiadoideae)and Galium tomentosum (Rubiaceae). The roots of Lannea schweinfurthii and other members of the genus are rich in phytochemicals, with at least some screenings for biological activity suggesting the presence of compounds that may affect the neurological system. In the absence of any comprehensive chemical or pharmaceutical analyses of vhulivhadza itself, the claimed memory-altering activities of this material can tentatively perhaps best be explained by psychological rather than physical (chemical)effects, but a more definite scientific explanation must await further study.