THE NIGERIAN TIMBER TREES 309 



The trees are sometimes cut down by the natives and used 

 for large dug-out canoes. The timber is termite-proof, and 

 the natives say that canoes made from this timber are very 

 durable, though rather heavy, and liable to become water- 

 logged when filled with water. It is of a dull reddish-brown 

 colour and has rather a coarse grain, 



Rutaceae. 



Zanthoxylum Seneijalense. Dry-zone African Satinwood. Ata, 

 Odan (Yoruba) ; Ughahan (Benin). 



It is found in the Ibadan, Abeokuta, Benin, Onitsha 

 and Ogoja provinces of Nigeria, at the edge of the mixed 

 deciduous zone and the lower part of the dry-zone forest region. 

 It is only a medium-sized tree, attaining a girth of about 

 4 feet and a height of about 50 feet. The bole always remains 

 armed Avith short, woody protrusions, each having a black 

 thorn at the apex. In the upper part of the bole and the 

 branches there are only thorns. The pinnate leaf has usually 

 three jjairs of pinna? and one end-leaf. All the leaves are broader 

 and about only half as long as those of Z. macrophyllum. On 

 the whole, this makes the foliage appear thicker, and, in fact, 

 gives greater shade than Z. macrophyllum. In proportion 

 the bole is shorter and the crown larger and more spread out 

 than in the case of Z. macrophyllum. The bole has a greater 

 tendency to divide lower down into three subsidiary stems, 

 thus spoiling the length of it for timber. The bunches of 

 small, black seeds are smaller than those of Z. macrophyllum^ 

 and if anything the seeds are also smaller too. 



The timber is very similar to that of Z. macrojihyllum,, the 

 sapwood and heartwood being the same colour, except that 

 the heartwood is often of a little darker shade, and bears 

 a greater proportion to the diameter of the tree than in 

 the case of Z. macrophyllum. On the whole it is harder, 

 and more often shows a little figure. Although it does not 

 reach such a large size, in many ways it is superior, the 

 grain being rather finer, and showing more sheen, and 

 if anything it works up to a finer texture when planed. It 

 is just as durable and termite-proof. It is a light-loving tree, 

 but will stand a certain amount of lateral shade. Owing to 

 the prevalence of grass-fires, it is slower-growing than Z. macro- 

 phyllum, but if anything it shades the ground better, and 

 considering where it usually stands, it is a slight soil-improving 

 tree. Natural regeneration is fair. No plantations have 

 been made with this tree. Samples of this timber have not 

 yet been exported, though, as it is a sister tree to the West 



