A preliminary classification of the healing potential of medicinal plants, based on a rational analysis of an ethnopharmacological field survey among Bedouins in the Negev desert, Israel.

In the course of an ethnopharmacological survey carried out among the Bedouins of the Negev desert, it was noticed that in addition to the use of modern medical services, medicinal plants were also being employed. We deemed it worthwhile, therefore, to investigate the current status of herbal medicine among the Negev Bedouins and to evaluate the relative efficiency of the plants used. To evaluate plant effectiveness by enquiries among patients once treated was found to be difficult and impractical. Hence, each interviewed informant was first requested to volunteer information on the plants and their uses. Next, to avoid the risk of memory failure, a list of 50 commonly used species was read out and the informant was asked to provide information on any that were familiar to him as medicinal herbs. Of 81 plant species mentioned by our 27 informants, 41 were named or recognized by more than 3. These species were arranged in accordance with the percentage of informants suggesting the same medicinal use for a given species as compared with the total number of informants reporting any sort of use for that plant. The obtained ratio was defined as the fidelity level (FL). The rank-order priority (ROP) of the plants was derived from these FL values. The relative popularity level (RPL) of the plants encountered was determined and plants were accordingly designated as "popular" or "unpopular". FL values were further adjusted, according to RPL value. We found that the bark of Phagnalon rupestre is widely used to induce deliberate burns for the healing of various ailments (ROP = 100), while infusion of the shoots of Teucrium polium, or of Artemisia herba-alba is employed to a lesser degree (ROP = 66 and 56, respectively) to relieve stomach disorders. Because the latter two species show fairly high ROP and are seen to be directly curative, they merit further investigation. Additional findings and implications of our ethnopharmacological survey are duly discussed.