Although ethnobotanical studies on herbaceous plants are available but studies on tree species are least. Keeping that view, the present work has been made to emphasize the immensely used tree species by the indigenous people of NE India. This book provides an exhaustive taxonomic account of 65 important tree species. Each species is described with author citation, phenology, ecology, associate species, distribution and uses.The result of the study has been based on extensive field work with collection of specimen, herbarium preparation, morphological characterization and identification. It is also supported by examination of authentic herbaria of species deposited at Botanical Survey of India (BSI). To facilitate identity and comprehension by the readers, the text is abundantly illustrated with 41 colour photographs representing the various taxa.