**1. Introduction**

At a global scale, available evidence points toward a direction of increasing relevance of Traditional Ethnobotanical Knowledge (TEK) as an invaluable, underutilized and underdocumented knowledge pool [1]. This presents developing countries, particularly in Africa, with a powerful tool to address plant resource conservation challenges [2]. In 1992, the

Convention on Biological Diversity (CBD) was the first to develop measures for use and protection of traditional knowledge related to the conservation and sustainable use of biodiversity. Abiding countries are expected to (1) promote the use of indigenous knowledge (IK) systems in natural resource management (NRM), (2) embrace and scale up utilization of indigenous knowledge and (3) promote equity and access in benefit sharing accruing from utilization of indigenous knowledge systems [3]. For example, Chapter 26 of Agenda 21 reiterates the "involvement of indigenous people and their communities at the national and local levels in resource management and conservation strategies to support and review sustainable development strategies" ([4], 26.3c). The United Nations Scientific Conference Organisation (UNESCO) and the International Council for Science Union (ICSU) in their blueprint documents appreciate the role played by IK and plead for its application in all forms of humanity engagements [5]. In defining TEK, various authors focus on the attributes of perception, management and utilization of plant resource by local communities [6, 7]. In specific terms, research on TEK focuses on "*how people classify, identify and relate to plant resources, examining the interactions of plants and people, taxonomic identification of selected plants and biological as well as chemical analysis of their ingredients*" [6]. Put differently therefore, TEK encompasses the investigation of plants as used in indigenous cultures for food, medicine, rituals, building, household implements, firewood, pesticides, clothing, shelter and other beneficial purposes [8, 9].

Indigenous knowledge, defined by Masango [10], as "*the totality of all knowledge and practices established on past experiences and observations that is held and used by people*," is the main reservoir of ethnobotanical investigations and is commonly referred to as TEK. However, changes in lifestyle brought about by globalization, particularly in Africa, have led to the negation of TEK in ongoing efforts to ensure sustainable management of resources with a concurrent loss of related knowledge [11, 12]. In particular, transmission of this knowledge between the older and younger generation is no longer connected [13].

In Kenya, for example, there is an apparent lack of practical recognition that indigenous technical knowledge is pivotal for sustainable utilization of environmental resources [6]. Further, TEK remains underdocumented in Kenya, particularly western Kenya [6]. Instead, there seems to be much focus on the "modern scientific knowledge." In western Kenya, for example, researchers do not seem to have paid much attention to TEK and its role in sustainable plant resource utilization. For this reason, this study sorts to answer the following questions: (1) Which plant resources are perceived as resources in western highlands of Kenya? (2) What degree of knowledge do people of varied socioeconomic status living in different ecological zones in western Kenya have about indigenous plant resources? (3) How are indigenous plant resources defined and conserved in western highlands of Kenya? and (4) To what extent do traditional knowledge and indigenous institutions for natural resource governance remain relevant in resolving current land degradation issues and how are they integrated in formal policy process in western highlands of Kenya? This study attempts to fill these gaps in knowledge by using people within western highlands of Kenya as the micro-level unit of analysis examining how they exploit indigenous plant resources. We postulate that people's management and utilization of plant resources are based on the knowledge, priorities and perceptions of the natural environmental resources and ecological processes involved. The study identifies the plant resources that are perceived by people as resources and undertakes an evaluation of these resources. It documents and assesses the TEK associated with the utilization of plant resources and examines how the resources are defined by use and culture.
