The debate over the substance and form of indigenous plant knowledge is often characterised by a divide between cultural (Harris, 1988) and biological (Boster, 1987) explanations that have proven to be theoretically weak. A holistic approach is needed to account for the interactive influence of a variety of variables on the development of indigenous plant knowledge (Boyd and Richerson, 1985). Efforts such as the Human Ecosystems approach advocate a processual study of how indigenous knowledge is influenced by dynamic circumstances found in a variety of social, cultural, biological and physical environments (Wyndham, 2002). I explore the contextual nature of Kiau Dusun plant knowledge in three ways: first, variations in the knowledge about different kinds of plants; second, variations in the knowledge that different people have about plants; and third, variations in the expression of plant knowledge in relation to circumstances in normative reality. I argue that Kiau Dusun plant knowledge reflects how the Kiau Dusun fit within the wider and localised frameworks of their human and natural ecologies. Free listing exercises and semistructured interviews along a plant trail resulted in quantitative data that, combined with surveys and participant observation, reveal intriguing patterns of how Kiau Dusun plant knowledge is fragmented. There is a growing body of declarative plant knowledge that no longer has a viable form of sustained practical application. Results also suggest that enacted plant knowledge concentrates mainly on plants that are directly relevant to the daily routine, in addition to innovative ways of interacting with the plant world such as tourism. Focus is given to the complex historical processes that continue to shape Kiau Dusun interactions and conceptualisations of the plant world, such that a salient body of Kiau Dusun plant knowledge reflects an ongoing and proactive negotiation about the relevance of plants in contemporary Kiau Dusun contexts.