The useful trees of northern NigeriaLely, Hugh Vandervaes
Science
The useful trees of northern Nigeria
Lely, Hugh Vandervaes
Plants, Useful -- Nigeria, Northern; Trees -- Nigeria, Northern
=The Fruit= is a long, broad, flat pod, covered with a green velvet.
It is about 12 inches long and 3 inches wide and splits with a report,
the two halves curling up and the seeds being violently projected. This
occurs in May and June.
=Uses.=—The young poles are used for local building purposes, but they
are very soft and liable to attacks from white ants and borer-beetles
and last only one season. Larger trees are locally cut into planks, and
provide an inferior timber.
[Illustration]
=ISOBERLINIA DOKA= Craib and Stapf.—_Doka_. LEGUMINOSAE.
This species, with its congener _I. Dalzielii_, is a type tree of the
Tree savannah and the most common of all trees in that formation. It
occurs as high-crowned forest over many hundreds of square miles of the
northern provinces, though it does not extend to the extreme north. It
is found in all stages according to age, from the dense covering of the
cleared farm land to the 40-50 feet high-crowned forests with little
undergrowth except that of its own shoots or seedlings. It grows long
straight boles, usually forking at 10-15 feet, and its wide-spreading
limbs form a high open crown which closes the roof of the forest.
Trees in a 25 feet forest have girths of, as a rule, not more than 2-3
feet, and the crown is ¾ of the total height, and narrow, the branches
ascending vertically. A girth of 5-6, or more, feet is common in trees
50 feet high. The species is very susceptible to fire and the majority
of large trees have hollow centres from this cause. The stem is often
a mere shell, filled with the earth of white ants or with a copious
volume of reddish sap which flows out and bubbles up from the base when
felled. This species seems to be more exacting as to soil conditions
than _I. Dalzielii_, the latter predominating on higher or more stony
ground, the change from one species to the other often being very
marked. As a rule the species are mixed indiscriminately, especially on
level country.
=The Bark= is dark grey with large, even-sized, rather shaggy scales.
It is darker and rougher than that of _I. Dalzielii_. The slash is
light red, the sap sticky.
=The Wood= is red, varying from bright red to greyish-red, with long,
silvery streaks. In transverse section the pores are large, in rows,
festoons and small groups, and the rays are extremely fine and close
together, showing as small red bars in radial section. In the plank the
pores are long, open red lines, the grain often being strikingly waved.
The sapwood is silvery with a reddish tinge. The timber saws and planes
well, with a smooth finish and no polish. The weight is 50-55 lbs. a
cubic foot.
Public-domain text, read in full here on John Shaqi.
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