Resins are an abundant and varied resource in the wet tropical forests of Southeast Asia. These exudates have been found archaeologically in Malaysia and are still exploited extensively by indigenous peoples. This paper analyzes the system of plant classification used by the Semelai of Tasek Bera who still exploit in many traditional ways their local forest resources. Two types of English terminological usage are presented in order to facilitate description of the Semelai classification system. Their complex and interlocking categories reflect the large range of useful natural substances found in their local environment. It is concluded that an understanding of their classification of plant fluids, which is largely based upon gross morphological features, also requires a knowledge of Semelai torch technology.