Ethnobotanical knowledge and threat factors for aloe species in Tanzania

Abstract

Background: The genus Aloe has long been known for its use in healthcare and cosmetics. In Tanzania, overexploitation is threatening some Aloe species with extinction and yet, little has been documented on the abundance and biocultural uses. Material and Methods: Semi-structured questionnaires were used to obtain ethnobotanical information from 236 respondents across 22 villages in four regions of Tanzania (Kilimanjaro, Tanga, Mara, Katavi-Rukwa). Results: A total of 23 Aloe species were identified, 20 of which were being used locally and were mostly being collected from the wild. We report the uses of A. mzimbana, A. volkensii subsp. volkensii, A. leptosiphon, A. parvidens and A. bicomitum for the first time in East Africa. The most preferred species were A. lateritia, A. duckeri and A. secundiflora which are three common, widely distributed species. Diseases frequently treated with Aloe species include malaria and general stomachache in humans, and Newcastle disease in chickens. Some Aloe species were found to have gone extinct locally due to over-harvesting. Rare Aloe species were perceived to be less preferred as they mostly occurred far away from settlements. Conclusions: We conclude that the genus Aloe is widely used across Tanzania and needs strong conservation measures to prevent individual species from becoming extinct in the wild.