198 WEST AFRICAN FORESTS AND FORESTRY 
possessed by grasses and low, scattered shrubs, often thorny. Never- 
theless, good pastures are often to be found, frequented by the Fulani 
in the comparatively short rainy season, and only at some points 
towards the French boundary do the conditions approach those described 
by Barth in the latitude of Zinder and Timbuctoo. For example, part 
of North Bornu, with a rainfall sometimes not exceeding 10 inches, may 
exhibit features entitling it to rank with the upper region of Chevalier’s 
“Zone Sahélienne.” A typical association in these scrub regions is 
familiar to the Hausas in three of the plants mentioned below, viz. 
the Sabarra, Guiera Senegalensis, the Magariya, Zizyphus jujuba, and 
the Dashi, Balsamodendron Africanum. Sokoto, with an average 
rainfall of 25 or more inches, still possesses thinly treed savannahs 
and bush-lands, with a vegetation composed of grasses, small sedges, 
low shrubs and the commoner leguminous and other weeds. 
Nor does the transition occur evenly across the whole region. In 
the eastern part between Kano and North Bornu the Acacia type 
prevails, and whole areas may occur occupied largely by Acacia Seyal, 
with yellow or rusty ochrey bark. On the western side Acacias, though 
present, do not appear to prevail, and between Kano and Sokoto there 
exists a stretch of broad-leaved forest in which most of the species 
found in Central Hausaland reappear, but after all these differences 
may be found to hold only over limited areas. 
The wide and well populated circle around large northern towns, 
highly cultivated and more or less stripped of trees to supply fuel 
does not quite display the natural conditions of the bush, where 
uncontrolled fires prevent natural regeneration of forest on cleared 
land, and where open grassy formations with stunted vegetation 
tend to encroach on the higher types of tree savannah. 
The species more characteristic of the northern drier belt within 
the Soudan Zone—if an arbitrary limit is allowed we may place it 
about 12° North latitude—may now be briefly indicated, though it 
will be understood that many of them are already present farther 
south. 
CaPPARIDACE# : most of the species of Capparis, Boscia and Merua 
existing farther south here prevail ; the low shrub Boscia Senegalensis 
is common, while Cadaba farinosa is a characteristic shrub. 
SIMARUBEZ: the Aduwa, Balanites Aigyptiaca, is a typical species 
of this region. 
Burseracez#: the Dashi, Balsamodendron Africanim, a shrub 
yielding African Myrrh, is familiar, with its congener B. pedunculatum. 
RHAMNACEEH: the Kurna, Zizyphus Spina-Christi, usually planted 
in towns, the Magariya, Z. jujuba, and the Magariyar kura, Z. 
mucronata, the last two being very characteristic of the open savannah. 
ANACARDIACEH: the Danya, Spondias sp., a fair-sized tree with 
yellow, plum-like fruit having a leathery rind, is abundant. 
