Northern Peninsular Malaysia’s forests are home to an extraordinary array of non-woody plants including ferns, orchids, rattans, and climbers which play critical yet underappreciated roles in maintaining ecological balance. This book explores the biology, ecology, and conservation of these plant groups, drawing on extensive field research and updated scientific insights. From the invasive spread of Dicranopteris spp. in disturbed landscapes to the fragile mycorrhizal relationships of terrestrial orchids, the chapters reveal how these species adapt, thrive, and interact with their environment. The rattan Calamus castaneus, for example, emerges as a key food source and seed-dispersal partner for forest fauna, while climbers shape canopy dynamics and serve as vital links in forest regeneration. In the face of increasing environmental pressures from habitat loss, invasive species, and climate change, this book highlights the urgent need to document, understand, and conserve these vital components of tropical biodiversity. Accessible yet detailed, this book is an essential reference for ecologists, conservationists, and readers interested in the hidden structure of Southeast Asian rainforests.