Wood anatomical features of some Nigerian species of Acacia Mill and their suitability for paper making

A comparative wood anatomical study of six species of the genus Acacia commonly found in Nigeria was carried out. Wood samples were collected from matured branches of plants in different locations in Mazah and Shere Hills, Jos, Plateau State, Nigeria. Transverse, tangential and radial longitudinal sections as well as wood macerates were prepared and mounted unto microscopic slides using standard anatomical methods. All the species had diffused porous wood, heterogeneous rays, aseptate fibres and predominantly solitary vessels with simple perforation plate, few pore clusters and pore multiples. Banded paratracheal axial parenchyma was common in all taxa except in A. senegal which was predominantly paratracheal without bands. Multiseriate rays were common features in all taxa except in A. nilotica which had predominantly uniseriate rays. Quantitative wood anatomical characters such as fibre length, fibre diameter, fibre lumen diameter, fibre wall thickness, vessel length, vessel diameter, ray length, ray diameter and pore diameter were of taxonomic importance in the delimitation of the studied taxa. The Runkel ratio of A. senegal (0.99µm) compared favourably with some hardwood species in the Nigerian rainforest ecosystem hence this taxon could be exploited for pulp and paper in Nigeria.