The anatomical characters of the wood of seven species of the genus Castanopsis (D.Don) Spach (Fagaceae) from northern Thailand
were investigated. The specimens were sectioned using a sliding microtome. Tissue maceration was also performed using Franklin’s
solution. The samples of wood sections and macerated cells were observed under a light microscope and under scanning electron
microscope. The wood anatomical data including presence of broad rays, vessel arrangement, presence of growth rings, occurrence
of tyloses, shape of vessel-ray pits, and occurrence of prismatic crystals are helpful for identification of the species. From this study,
a key to species based on wood anatomical characters was constructed.