Vascular differentiation and similarities is a function of anatomical diagnosis of plant species. Various lines of taxonomic evidence have been drawn on the four Anthocleista species recorded in southern Nigeria; however, not much effort toward the anatomy of the four taxa has been made. Thus, the aim of this study was to determine the importance of their vascular similarities and variation in the taxonomy of the genus; with the objective of investigating the anatomy of the leaf, petiole, root and stem of the species and by implication access the suitability of the diagnostic features for possible taxonomic delimitation. The result has revealed similarities in the four studied anatomical indices (foliar, petiole, root and stem) among the species. However, there were distinct variations as follows: hypodermis, endodermis, and air sac in the foliar anatomical features; idioblast, spongy cell, intercellular spaces and vascular bundles in the petiolar anatomy; exodermis, sclereid, pericycle and vascular bundles in the root anatomy, while cortex, collenchyma and vascular bundles were variations in stem anatomy of the species. Therefore, with the variation based on distinguishable anatomical characters; the Anthocleista species can be segregated from each other on the basis of their quantitative anatomical parameters in diverse features of the anatomical indices. This consequently can be a panacea for ethnobotanical and economic valuation of the species based on its therapeutic potentials as antimicrobial agent, medicine, antioxidant, hypoglycemic agent, anticorrosion agent and environmental bioindicator.
Key Words: Anatomy, Foliar, Petiole, Stem, Root