In parts of the tropics, medicine and pesticides collected from wild trees, shrubs and plants play a vital role in the health of people, their livestock and the protection of their crops. The high proportion of the population using traditional herbal medicine (THM) is often due to lack of adequate and accessible medical treatment and based on tradi - tional and cultural practice and preference due to perceived efficacy [67]. For example, the Kenyan medical health care system serves only 30% of the population, thus the implication is that the remaining 70% (estimated to be 21 million people) are outside of the primary health care system and may rely on and use traditional forms of health care such as THM and the use of medicinal tree and shrub material [68]. Other factors contributing to the high use of THM in Eastern Africa include population increase, grow - ing urbanization, poverty, disease epidemics especially malaria and tuberculosis, the emergence of chronic conditions, and environmental instabilities [69]. Many of these factors are relevant to the drylands, which constitute 69% of the region and lag behind in terms of access to health care for humans and livestock. Medicines and pesticides from trees and shrubs have significant potential, but poor scientific evaluation, valida - tion and documentation impede wider use [70]