130 
so much farther south of the Equator than north of it. Only 
nine of the fifty-four species are known to occur north of the 
Equator, five of them being confined to that area. 
The species are mainly restricted in distribution to the dry 
Savannah Forest of the Great Central Plateau; only a few 
(possibly ten) are found in the coastal rain-forest area below 
600 ft. elevation. The majority (80 per cent.) occur on the 
nee plateau lying between Angola and Nyasalan 
the 54 species known, 34 are endemic in a single State, 
13 in naa States, and 3 in three States, leaving only four species 
(B. Woodiana, B. utilis, B. apertifolia and B. Randi) widely 
distributed. 
The distribution and endemism by States is shown in the 
following table :— 
Number 
of species. ~ Endemics. 
Kenya Colony - - - - 2 1 
Uganda Protectorate - -~ - 1 0 
Tanganyika Territory - - - 16 10 
Nyasaland Protectorate -. - 9 3 
Portuguese E. Africa - - - 7 1 
Rhodesia = - - - - i7 4 
Angola 10 6 
Belgien: Cdngo (Katanga Province) 18 6 
Upper Guineas - 6. 5 
36 
Habit.—All the species of Brachystegia are trees with fibrous 
bark sometimes containing tannin; in this respect they contrast 
sharply with the allied genus Ute stoatenlass: which is always 
an undershrub with annual shoots from a woody rootstock. 
Leaves——-The leaves are always alternate and paripinnate ; 
the leaflets vary greatly in number, ranging from about 60 pairs 
(B. microphylla) to 2 pairs (B. Gairdnerae, page 142, fig. 11). 
It is of interest to note that the latter extreme reduction is 
accompanied by the entire suppression of the sepals; B. Gairdnerae 
is apparently the most reduced example of the genus. Useful 
specific characters are derived from the position of the midrib, 
which is almost marginal in some species (B. taxifolia, etc.). 
The leaflets are always opposite except in B. filiformis, where 
they are rarely subopposite, and in B. Klainei (page 142, fig. 4), 
in which the lower are quite alternate and the terminal opposite. 
So far as is known the leaflets are sensitive and they are 
often closely imbricate when specimens are gathe 
Stipules and Stipels—The stipules furnish a useful character 
for the subdivision of the genus; in the majority of the species 
they are very early deciduous and are not present at the time 
of flowering. In about 10 species, however, they are more Or 
less persistent and have a broad foliaceous base with a long 
