Significance of Wood Anatomical Features to the Taxonomy of Five Cola Species

Wood anatomy of five Cola species was investigated to identify and describe anatomical features in search of distinctive characters that could possibly be used in the resolution of their taxonomy. Transverse, tangential and radial longitudinal sections and macerated samples were prepared into microscopic slides. Characteristic similarity and disparity in the tissues arrangement as well as cell inclusions were noted for description and delimitation. All the five Cola species studied had essentially the same anatomical features, but the difficulty posed by the identification of Cola acuminata and Cola nitida when not in fruit could be resolved using anatomical features. Cola acuminata have extensive fibre and numerous crystals relative to Cola nitida, while Cola hispida and Cola millenii are the only species having monohydric crystals. Cola gigantica is the only species that have few xylem fibres while other species have extensive xylem fibre. These features have proved very functional and strongly of diagnostic value in the classification and delimitation of the studied Cola species.