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. 
Rutacez. 
Zanthoxylum Senegalense. 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 with 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 pairs of pinnz 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. macrophyllum, 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 
