the calyx tube shrunk and the toothed disc being exposed. It enlarges
up to 6 inches in length and is constricted at intervals so that it
looks like a string of irregular-sized beads. Sometimes two seeds
lie alongside, and there may be as many as 30. The fruit is yellow
and finally brown when ripe, and is similar in appearance to that of
_Cassia goratensis_, though the restrictions are not so narrow as those
of that species.
[Illustration]
=MAERUA CRASSIFOLIA= Forsk.—_Jiga_. CAPPARIDACEAE.
A medium-sized tree from 15-30 feet high and up to 4 feet in girth,
which grows in dry localities as far north as 14°. It is quite common
in N.E. Sokoto. It has a short bole, up to 12 feet, with ascending
branches and can be at once distinguished by its heavily pruned
appearance, the lateral branches being very short and resembling
_Randia nilotica_, the rosettes of leaves being borne on stunted shoots
on long, straight, tough branches. The form varies from the short tree
with wide, compact crown to the tall, narrow growth of larger specimens.
=The Bark= is dull grey, smooth in young trees and longitudinally
scaled in older trees.
=The Leaves= are in tufts at the end of short woody shoots and are ¾
inch long and ⅓ inch wide, tapering at the base, with a broad tip, in
the shallow cleft of which projects the mid-rib. They are a dull, dark
green and limp and leathery in texture.
=The Flowers= which appear in February rise from the leaf-bearing
shoots on ½ inch stalks. Each has a calyx of 4 sepals, light green,
which fall back to the stalk with maturity, some 30 white stamens with
green anthers, all rising from a short column, and a long pistil with
thickened stigma. There is a faint perfume.
=The Fruits= are like those of _Maerua angolensis_; long, jointed pods
formed by the growth of the clubbed pistil. They are brown when ripe
and break into sections. The seeds are 10-20 in number and ripen about
April.
[Illustration]
=MIMOSA ASPERATA= Linn.—_Gumbi, Kaidaji, Kardaji_. LEGUMINOSAE.
A very common shrub which inhabits marshes, the banks of rivers and the
fringes of lakes, in fact, any low-lying, inundated ground, forming
dense, impenetrable thickets, often of large extent. On the banks of
rivers it is frequently associated with a species of _Salix_ or willow.
It has numerous stems and long erect or drooping shoots, 10 to 12 feet
in length. The whole plant is covered with hairs.
=The Thorns= on the stems are in three’s, below each leaf, one thorn
directly under the leaf, with a pair a little higher up on either side.
The thorns on the stems are all the same size and shape, but those on
the leaves differ as described below.
=The Leaves= are 3-5 inches long with 6-8 pairs of pinnae, bearing up
to 40 pairs of long, narrow leaflets. The leaf is sensitive and folds
up tight in the evening, the leaflets falling back under the mid-rib.
On the upper side, between each pair of leaflets, is a short, slender
and very sharp thorn, pointed well forward, and between the lower 4 or
5 pairs is a pair of sharp thorns with broad bases in the same plane as
the leaflets. These thorns are absent in the upper part of the leaf.
The young leaf is hairy.
=The Flowers= are in spherical heads about ½ inch in diameter, either
white or mauve. Each minute flower has a calyx of 4 sepals, 8 stamens
with white or mauve filaments and white anthers, and a long pistil.
=The Fruits= are pods, 2-2½ inches long, ½ inch wide and ⅛ inch thick,
slightly curved. They are covered with erect, bristly hairs whose tips
curve forward. On the green pod these hairs are golden brown; on the
ripe pod they are unpleasantly penetrating. The pod splits transversely
into 15-20 segments, each containing a small bean. The outer rim of the
pod remains intact, the sections dropping out in the same manner as
those of _Entada sudanica_.
=Uses.=—It is used as a fence round farms for protection against
grazing, and in places where there is an acute shortage of fuel demands
a price in the markets.
[Illustration]
=MITRAGYNE AFRICANA= Korth.—_Giyeya_. _Giyaiya_. RUBIACEAE.
A large tree which inhabits “fadammas,” “tabkis” or annually inundated
areas. It has several erect, straight stems ascending to a height of
60 feet in large specimens and the foliage reaches almost to ground
level. From the branches, especially noticeable when one of these is
horizontally inclined, are a number of slender erect shoots, like those
of pollarded willow. The crown is the same width throughout with a
narrowed or pointed top. The tree coppices very well and would provide
a rotation crop if properly worked. It will not stand drought and a
succession of dry years will kill the tree, subsequent wet years only
serving to rot the dead trees. This is of frequent occurrence in the
farthest north.
=The Bark= is light brown or grey and smooth, a few scales showing on
the lower part of the stem in season. The slash is light brown, rapidly
darkening.
=The Wood= is a very light brown. In transverse section the rings
show broad bands of a darker colour, a purple tinge which is clearly
seen in vertical, especially radial sections. The pores are minute,
quite invisible to the naked eye, and with difficulty seen with the
lens, in rows between the extremely fine rays which are waved and very
close together. The grain is very close and fine; seasons well and is
slightly liable to borer beetle attacks, works well with all tools, the
plane producing a nice clean finish of a velvety nature. It is one of
the best all-round timbers for many purposes and its small sizes are a
great misfortune. The weight is 40 lbs. a cubic foot.
=The Leaves= vary somewhat in shape from a narrow oval to a broad,
rather square oval, both shapes with a pointed tip. They are 3-4 inches
long and 2-2½ inches broad with ½-¾ inch stalk. They are in opposite
pairs as is so typically seen at the base of the flower or seed head.
They are paler beneath than below, very soft and thin in consistency
and the venation appears almost white by contrast.
=The Flowers= are in yellowish balls an inch in diameter, sweet-scented
and appearing at the beginning of the rains, though a few blooms may
be found at odd seasons. Each flower is about ½ inch long with 5 long
sepals narrow at the base, broad at the tip (obconical); a tubular
corolla with 5 lobes between each of which protrudes the anther of a
stamen, grey in colour; and a long pistil terminating in a reddish
stigma, shaped like a bee-hive. The flowers are at first white and then
turn yellow.
=The Fruits= are in spherical heads ¾ inch in diameter and dark brown
in colour. Each fruit is what is called di-coccous, _i.e._, the fruit
is formed of two separating carpels, containing seeds. The fruiting
heads are most conspicuous and enable the tree to be identified from
some distance.
=Uses.=—The timber has been used lately by the Industrial Schools with
great success, and in Sokoto it has been found one of the best for
all purposes where large sizes are not necessary. The native makes
bowls and spoons from it and it is a good source of poles for building
houses. It is supposed to rot rapidly if exposed to wet.
[Illustration]
=MONOTES KERSTINGII= Gilg.—_Wasani, Gasa kura, Farin Rura_.
DIPTEROCARPACEAE.
A small tree of the better types of savannah not extending much north
of 11°, and very locally distributed. In certain localities, _e.g._,
S.E. Sokoto and W. Bauchi, it is very abundant and over hundreds of
square miles will be found pure in patches and elsewhere composing
40-50 per cent. of the growth. It is slender, erect, up to 30 feet
in height, with a stem of 1½-2 feet in girth, with the stem bare of
branches up to 10 feet and the crown high, open and narrow. Trees in
the open will grow large, round, compact crowns. The distinguishing
features are the very light under surface of the leaf and the enlarged
sepals which surround the fruit. The species resembles _Parinarium_.
=The Bark= is grey with light patches and fairly smooth, with small,
close-fitting, not very prominent scales. The slash is dark red.
=The Wood= is a light brown-pink. In transverse section the rings are
distinct as numerous very close fine lines, the pores are minute,
numerous and crowded in small festoons interspersed with numerous
single pores, the soft tissue being poorly developed. The rays are so
fine and close as to be only just visible with the lens. The grain is
very close and wavy and the planed surface reflects the light so as to
produce a “shot” appearance, with a sheen. The wood is very hard to
work with saw and plane and very cross grained. The weight is 64 lbs. a
cubic foot.
=The Leaves= are oval, some 4 inches long and 3 inches broad, slightly
cordate at the base, broad at the tip, with a ½ inch long downy stalk.
The upper surface is dark green, shining and rough to the touch, with
the venation below the surface, and the mid-rib bends at each lateral.
The under surface is grey and velvety, the whole venation being
prominently marked. At the base of the leaf there is a curious oval
space where the blade of the leaf meets over the stalk at the bottom
and again at the third lateral, leaving a gap through which the base of
the mid-rib seems to appear.
=The Flowers=, which appear in the rains, are in small axillary
clusters, each about ½ inch in diameter, with a 5-pointed calyx, 5 long
white pointed petals, a mass of long stamens filling the corolla and a
short straight pistil. They are very inconspicuous.
=The Fruits= are capsules, ½ inch in diameter, roughly round and
wrinkled when ripe, with 3 cells in each of which is a small seed
loose in the cell. The capsule is hard, fibrous and loosely porous
in transverse section. Round it are the 5 greatly enlarged sepals,
modified into wings, bright red at first, then drying pale brown. The
fruits are very persistent on the tree, many not falling till the new
leaves appear. The red wings are conspicuous from a great distance.
[Illustration]
=MORINGA PTERYGOSPERMA= Gaertn.—_Zogalagandi, Bagaruwar Makka_.
MORINGACEAE.
This is a very familiar little tree, an exotic from India, which is
planted in compounds in the north. It grows some 15-25 feet high with a
single stem often forking or dividing into 2 or 3 stems at or near the
ground. It is distinguished by its tripinnate leaves, white flowers and
long triangular, pointed pods.
=The Bark= is a deep bluish grey and smooth.
=The Wood= is white, very soft and of no use whatever.
=The Leaves= are tripinnate, about a foot long, with some 6 pinnae,
each with some 2-5 pinnules, some again with one or two pairs of
leaflets and a terminal leaflet. The terminal leaflets are generally
larger than the others and all are variable in size and shape from
small oval to large spear-shaped leaflets. The foliage is very sparse
and graceful.
=The Flowers= are white, in loose panicles, in flower for many months
in the year, during the dry season. Each has a 5-parted calyx with
unequal sepals, 5 white petals, the 2 upper ones smaller than the
others, 5 stamens with and 5 stamens without anthers, and a slender
style. The flowers are sweet-scented.
=The Fruits= are long, triangular capsules up to 18 inches long,
slightly jointed, with 2 grooves down each side, a sharp beak at the
tip, light brown in colour and splitting down the 3 edges to release
the seeds. These are blackish with 3 papery wings so shaped as to
overlap and fit into one another, the bottom of the one seed touching
the top of the wings of the one below it. The white pith, with a sheen,
is indented to hold the seeds.
=Uses.=—It is commonly used as a fencing to compounds, the mats or
cornstalks of which the fence is composed being tied to the growing
trees. The roots are eaten as horse-radish and the leaves fresh as a
vegetable. The seeds yield a very fine oil (oil of Ben) which has been
pronounced as suitable for watch lubrication.
[Illustration]
=OCHNA HILLII= Hutch. OCHNACEAE.
This is a small tree, common locally in parts of Zaria, Bauchi and S.
Sokoto, not extending north of 12°. It is as a rule slender and erect,
up to 15 feet in height, older trees forming a round crown, younger
ones often shrub-like. The yellow flowers and red and black fruiting
stage are very conspicuous and the serrate obovate leaves are typical.
=The Bark= is smooth, a dull grey or brown, with small scales. The
slash is yellow, rapidly darkening on exposure.
=The Leaves= are obovate, 3-4 inches long, 1½-2 inches broad, with
cleft tip and finely serrate edges. The venation is prominent on the
upper surface. The young leaves are shiny and tinted red, and the
mature leaf is tougher and grey-green with a waxy bloom.
=The Flowers= are borne on a short woody shoot, 4 or 5 together with
1-2 inch, slender stalks. Each has a calyx of 5 pale green overlapping
sepals, 5 yellow petals smaller than the sepals and a ring of numerous
stamens round an erect pistil. The flowers appear in February or March
and the petals sometimes only remain 24 hours on the flower.
=The Fruits= are drupes, or small plums, in a ring round the much
swollen torus or disc. The sepals enlarge and turn crimson, as does the
disc, and the seeds, at first green, turn black and shiny, shrivelling
when the surrounding pulp dries up. The branches are often borne down
by the weight of the large crop of fruit which is a most conspicuous
feature. The elongated pistil and the remains of the stamens appear
like bristles on the torus. Most of the seeds are destroyed by a grub.
[Illustration]
=ODINA ACIDA= Walp.—_Farun mutane_. ANACARDIACEAE.
A large tree, similar in flowers, fruits and leaves to _O. Barteri_,
but differing in the absence of hairs on leaves and flower spikes to
the extent of those on _O. Barteri_, and distinguished from it at once
by the very smooth bark. It reaches large sizes, but not great heights,
the average proportion being some 30 feet high with a girth of 6-8
feet. A very short, stout bole divides into a number of large, widely
spreading limbs, the twigs drooping down to near the ground. The crown
is open and rounded and of great width, affording little shade. Its
habitat is the granite country, where it grows in large quantities on
the plains or up in the rocky hills, stunted specimens flourishing on
almost bare rock with the roots in the smallest cracks. The branches
are very flexible and can be bent almost double without snapping. It
is called “Farun mutane” as against the “Farun doya” of _O. Barteri_,
because it is used for food and medicine.
=The Bark= is silvery grey, smooth to the point of shining, with
occasional scales and a few lenticels. Very old trees cast large
scales from the lower trunk. The bark frequently shows a marked spiral
twisting round the stem and there are folds and creases like a skin.
Resin exudes from the slash which is light red and of crumbling texture.
=The Wood= is practically the same as that of _O. Barteri_, q.v., for
the most part consisting of a soft, dirty white wood, readily sawn and
planed and of little value, the small heartwood being red-brown. The
weight is about 25 lbs. a cubic foot.
=The Leaves= are pinnate, 18 inches long with some 4 pairs of leaflets
and a terminal leaflet. These are broad at the base, narrowing towards
the tip, the margins sinuous, the basal lobes unequal, the short stalks
flattened, the upper surface light green, shining, with a few hairs and
a pronounced stickiness to the touch. They appear after the flowers.
Young leaves are very slightly tinged red.
=The Flowers.= The spikes of both sexes appear from January to April.
The male spikes are up to 9 inches in length, the flowers in irregular
clusters with gaps, especially on the lower part of the spike, without
flowers. Each has a small, 4-part calyx, 4 petals and 8 short, erect
stamens. A few hairs are scattered about the spike, which is scented.
The female spikes are some 3 inches long and sparsely flowered. Each
has a small, 4-part calyx, 4 petals, the rudiments of 8 stamens and a
rounded ovary with 4 stigmas. There is no scent. Though the spikes of
both sexes appear well before the leaves, they may persist till the
leaves are practically full grown.
=The Fruits= are similar to those of _O. Barteri_ but very shiny.
They hang in dense clusters of spikes, ripening from green to red to
a purplish black, resembling cherries. There is a thin skin and juicy
flesh round a large, hard stone containing a white kernel attached to
the top and not filling the cavity. The fruits ripen in June and the
crop is often prolific.
=Uses.=—The fruits are eaten fresh. The bark is boiled in water and the
infusion taken as a medicine for stomach troubles.
[Illustration]
=ODINA BARTERI= Oliv.—_Farun doya_. ANACARDIACEAE.
A very common tree in open savannahs, flourishing in deep or shallow
soils, preferably of granite composition, and plentiful amongst rocks.
It is a large tree up to 40 feet in height with girths of 6-8 feet
and its characters are a short bole, rarely over 10 feet, and large
spreading limbs forming a wide open crown. The branches are very
pliant and the twigs droop. This and _O. acida_ occur over large areas
together, the rough bark and hairy leaves distinguishing the former.
=The Bark= is almost black and very rough, with deep, vertical fissures
and long heavy scales which fall in large ragged lengths. The stem is
thus often very shaggy. The slash is salmon pink with paler streaks.
=The Wood= is dirty white, with bluish and brown discolorations. In
transverse section the rings are indistinct; the pores are very small,
numerous, single and fairly evenly distributed; the rays fine and close
together, hardly visible to the unaided eye. In vertical section the
grain is rather coarse, there are no bands of colour and often a number
of small knots. The wood is soft, of poor quality, easily worked and of
the quality of _Bombax_. The weight is only 25 lbs. a cubic foot.
=The Leaves= are some 18 inches long, pinnate, with some 4 pairs and
a terminal leaflet. These are spear-shaped, about 4 inches long and
2 inches wide, with very short, thick stalks. They are dark green,
densely covered with short hairs and limp and flaccid. The young leaf
shoots are a reddish-brown and densely pubescent.
=The Flowers= are in spikes, the male and female on separate trees.
The male are in 5-6 inch spikes, up to a dozen spikes at a twig tip,
often so numerous on the leafless tree as to render it conspicuous from
a great distance. They appear from January to April, and are scented.
The flowers are in clusters round the spike, not completely covering
it. Each has a 4-lobed calyx, 4 small petals, 8 erect stamens and the
rudiments of an ovary with 4 stigmas. The flowers fall from the spikes,
leaving them bare. The female flowers are on shorter spikes, the
flowers are fewer in number and evenly distributed on the spike. Each
has a 4-lobed calyx, 4 small petals and an ovary with 4 stigmas. They
are not scented. Both spikes are very pubescent.
=The Fruits= are nuts, flattened ovoids with the stigmas prominent at
the tip. They ripen about March to May and are reddish purple, the
flesh very resinous and the white kernel attached to the top. They are
½ inch long and are borne in heavy clusters of spikes, generally erect
and stiffer than those of _O. acida_.
=Uses.=—No part of the tree is edible as in the case of _O. acida_.
[Illustration]
=ORMOCARPUM BIBRACTEATUM= Baker.—_Faskara giwa_. _Tsa_. LEGUMINOSAE.
A small, erect tree up to some 25 feet in height with 1-2 feet girth,
locally very plentiful but otherwise infrequent, _e.g._, in the Anka
district of Sokoto it occurs in vast numbers, but nowhere else in
the province, and in one or two places in Bauchi small clumps of it
are seen. At first sight it is very like an _Acacia_, with its erect
branches and pinnate leaves. The stem branches generally low down,
occasionally at a height of 8-10 feet, and the branches are vertical,
so that the tree has no width of crown. Owing to the scarcity of the
smaller branches the vertical ones are crowded with leaves, and from
February to April with flowers, for several feet, there being no side
twigs, these being replaced by small shoots covered with bracts.
=The Bark= is silvery grey with a soft sheen, smooth and very thick,
large scales peeling off in season. The effect of fire on young stems
is to produce great bosses of light brown cork, often charred. The
slash is yellow.
=The Leaves= are about 2-3 inches long, pinnate, with some 6-8
opposite or sub-opposite leaflets and a terminal leaflet. These are
¼-⅜ inch long and about ³⁄₁₆ inch broad, oval, with or without a
slightly notched tip in which the mid-rib protrudes slightly. They are
grey-green and hairy and each springs from between a pair of bracts on
the twig.
=The Flowers= are very handsome “Pea-flowers” in small clusters on long
stalks, branched, with a bract at each branch, springing from small
clusters of bracts on the woody stems. The stalks are purple and hairy,
the calyx is irregular, purple and green, and the corolla is a delicate
pink with a pale green keel. The flowers are generally in great masses
and a curious characteristic is that they dry up and retain almost
their original shape, the pod ripening meanwhile.
=The Fruits= are small black jointed pods 1-1½ inches long with some
4-5 joints, oval, flattened and hairy, each containing one seed, pale
brown in colour. The pod will often bend right round and its tip enter
the mouth of the flower.
[Illustration]
=OSTRYODERRIS CHEVALIERI= Dunn.—_Durbi_. LEGUMINOSAE.
A large tree some 40 feet or more high, common in some parts of Sokoto,
Zaria and Katsina, but very local in its occurrence and extending as
far north as 13°. The girth is up to 7 feet, more often 5 feet. It
closely resembles _Paradaniellia Oliveri_ in bark and leaf and form,
especially in young trees of the latter species. The bole may be clean
and straight for 20 feet and the crown is high and flat-topped in full
grown trees. It does not grow on poor soils and its extension to 13° is
by way of moister valleys and pockets of alluvial soil. The pods and
flowers are the distinctive features.
=The Bark= is light grey with a strong resemblance to that of
_Paradaniellia Oliveri_, the scales being even-sized, polygonal but
not so large as those of _P. Oliveri_. Nor has it the red tinge of the
latter. The slash is most distinctive, being a mixture of fibres of
white, dark brown and crimson, like strands of wire.
=The Wood= is whitish or cream-coloured. In transverse section the
rings are indistinct but the concentric lines of hard and soft tissue
are well marked. The pores are single or in small groups, unequally
scattered. The rays are invisible to the unaided eye, and waved
slightly. In vertical section the pores are long and open, the hard and
soft tissue well marked in parallel lines and the rays show as long,
fine bands on the radial section. The wood is soft, medium weight,
shows red streaks, is easily worked and the planed surface is smooth.
It has a curious smell, The weight is 45 lbs. a cubic foot.
=The Leaves= are pinnate, 10-15 inches long with some 6 pairs and a
terminal leaflet. The leaflets are opposite or nearly so and increase
in size towards the top pair, the largest 3 inches long and 1½ broad,
with cordate base, unequal lobes and an even taper to a rounded, cleft
tip. The upper side is bluish-green with a bloom, the underneath pale
grey-green. The venation is prominent beneath.
=The Flowers=, from February to April, are in erect panicles on the
stout twig ends, some dozen or so on each twig. Each flower is white,
papilionaceous, ¾ inch long. The calyx is covered with brown hairs, as
are the flower-stalks and there is a green splash in the centre of the
standard petal. The panicles are 6-8 inches long, gradually drooping.
=The Fruits= are pods, at first limp and green, then brittle and
dark brown. They are 3-6 inches long, 1¾ inches broad, flat and
strap-shaped, the surface veined, and a prominent ridge runs round the
outside a little way from the edge, outside which ridge there is no
veining. The seeds, more often 1 than 2, are slightly embossed, and
are flat, brown, round beans with a white hilum. The pods ripen from
May onwards and numbers of them persist on the tree till the following
flowering season.
[Illustration]
=PARADANIELLIA OLIVERI= Rolfe.—_Maje, Kadaura_. “_Copaiba Balsam
Tree_.” LEGUMINOSAE.