Marginal Parenchyma Bands and Crystalliferous Chains as Indicators of Age in African Acacia Species

Abstract

The radial cross sections of wood samples from individuals of known age in six African Acacia species were examined for growth rings, which were apparent in most species as narrow bands of marginal parenchyma filled with long crystal chains. The number of bands formed annually corresponded to the number of peaks in rainfall distribution. Samples from specimens of African Acacia species from the Oxford Forestry Institute's xylarium (FHOw) were also examined for similar crystalliferous chains, which were generally present. These results suggest that marginal parenchyma bands and crystalliferous chains define growth phases in African Acacia species, and may therefore be useful for age determination.