In describing the woods, few of which are in use and many of which are little likely to be of use, an attempt has been made to strike a path midway between the complete technical and botanical description employed with regard to timbers and a vague statement as to colour, quality, hardness and grain which helps little to distinguish the individual from others like it. Most of the woods are described from samples collected by the author and shaped by the Sokoto Arts and Crafts School. I am indebted for these, and for the facilities offered for observing their behaviour under tools, to Mr. W.E. Nicholson. The dry weight of seasoned wood is given in all cases and in this connection it may be noted that a number of species produce heavier wood in the north than they do in the south. A table of flowering seasons has been appended, with a few notes on its significance. A second appendix arranges the 120 species under their Families. The _Genera Plantarum_ of Bentham and Hooker has been followed. Finally, there is an index of _Hausa_ names for reference to the plates and text, whose numbers are given in the index. A blank column has been left in the index for the benefit of those who may desire to collect either additional _Hausa_ names or the nomenclature of other tribes. It is hoped that the scope of the volume will be enlarged thereby, so as to cover other parts of Nigeria where the trees are the same but the language different. The botanical name, being universal, is always given preference. The native names, variable and unreliable as they often are, should be a secondary consideration, their importance resting in their being a means of communication with the native rather than a short cut to the botanical names. In a country where there are several native names for one tree or one native name for several distinct species, the knowledge gained is either limited to a small number of trees or applicable to a small area of country. But once examined and properly identified, no number of native names need confuse the real identity. In collecting native names a warning should be given against the ignorant or ready-to-please native, and independent corroboration is advisable before accepting a name as worth recording. At the same time it is a fact that names genuinely differ in quite small areas of country where the same language is spoken, and a knowledge of the botanical names or real familiarity with the tree species is essential to reliable work. The identification of 120 species, though seemingly not a large number, is sufficient to afford a thorough familiarity with most of the savannah forests and makes further species, not included here, stand out all the more clearly from their no longer similar companions. Numbers or economic values of further species are sufficient justification for forwarding these for identification to Kew, if they cannot be named from their resemblance to known species or by means of a Flora.