The dimensions of vessels and rays in the trunk of a fully grown tree of Afzelia africana were measured under the light microscope in order to obtain their actual lengths and widths in micrometer (µm). 50 measurements each of vessels and rays were carried out and their average means were determined using ANOVA and Duncan Multiple Range Test (D.M.R.T). The average length of vessels in the trunk were 0.37±0.20, 0.36±0.10 and 0.37±0.30 for the top, middle and basal portions while the average width were 191.92±0.30, 202.14±0.10 and 207.17±0.20 for the top , middle and basal portions of the trunk respectively. There were no significant differences (P≤0.05) in lengths of vessels from the base to the top of the trunk as well as from the core to the outer potion. Conversely, there were significant differences in the width of vessels from base to the top of the trunk as well as from the core to the outer portion. The ray cells, on the other hand, had 0.40±0.40, 0.38±0.30 and 0.37±0.20 as average mean lengths for the top, middle and basal portions of the trunk whereas, for these same portions the mean width of the ray cells were 49.41±0.20, 48.05±0.30 and 51.54±0.50 respectively. No significant difference was observed in the lengths of rays from the top to the base as well as from the core to the outer. Conversely, there were significant differences in the width of rays from base to middle but not from middle to top. In the same vein, there were significant differences in the width of rays from core to outer. Morphologically, the vessels were narrow, short, open-ended with simple perforation plates, and pits while the rays were multiseriate and heterogeneous. It was opined that the nature and dimensions of the vessels and the ray cells of this tree plant could be of physiological and pathological advantages to this taxon.
