This volume is a compendium of selected plant species of ethnobotanical value to the highland communities of popular Southeast Asia. “Traditional” knowledge held by local communities on their resources is always in flux and adapting to a quickly changing environment. New plants find their entry into the local pharmacopoeias, while existing ones maybe removed. Likewise, various local communities might find the same plant useful for completely different purposes. While compiling information on the species, authors have taken great care to ensure that the dynamic nature of ethnobotanical knowledge is represented adequately. Special emphasis has also been given to cultural value of species to the local communities in the region. The field (and thus the market) of ethnobotany and ethnopharmacology has grown considerably in recent years. Student interest is on the rise, attendance at professional conferences has grown steadily, and the number of professionals calling themselves ethnobotanists has increased significantly (the various societies (Society for Economic Botany, International Society of Ethnopharmacology, Society of Ethnobiology, International Society for Ethnobiology, and many regional and national societies in the field currently have thousands of members). The objective of this new Major Reference Work on Ethnobotany of Mountain Regions of Southeast Asia is to take advantage of the increasing international interest and scholarship on highland landscapes and communities. While ethnobotanical studies are now available from many regions of the world, no comprehensive encyclopedic volume on the highlands of popular SE Asia is available in the market. We include the best and latest research on a full range of descriptive, methodological, theoretical, and applied research on the most important plants for the region. Scholars in plant sciences worldwide will also be interested in the dedicated website for this volume and its dynamic content.