Chapter VIII: Nigeria (3)

Since 1901, a moderately large Arboretum has been planted at Olokomeji, containing quite a number of indigenous trees growing under natural conditions, according to the type of climate found in that locality, and also some exotic trees which grow in similar climates in Asia or South America. In a comparatively short time the new Forest Officer can get a very fair idea of the most important timber trees found locally, as well as elsewhere. In connection with the work of renewing the labels on specimen trees, ocular demonstration of all these trees is obtainable. The local Ranger can usually supply the vernacular names, and here is a wide field for linguistic qualifications. Yoruba is the local language, Benin is spoken by a large number of people in the Central Circle, and Hausa by nearly all itinerant traders throughout the country. Ibo, another language, is spoken by nearly 3,000,000 inhabitants, while many of the Cross River people (Eastern Circle) speak Efik; some, however, speak New Calabar or Ibibio, while again, in a large part of the Niger Delta, Brass or Ijor is spoken. Sooner or later the language of the locality should be acquired, and in fact this is prescribed by Government order as a necessary preliminary to the granting of the first increment.

The routine office work includes simple book-keeping, analysis of records, appointments of staff, the engagement of native labour and all payments. The executive work outside is carried out by the Forest Guards, Foresters, and Rangers, who require constant supervision. Owing to the distance, only some of them can report at Forest Headquarters each month, and the rest must be seen when the Forest Executive Officer makes his tour of inspection. If possible, travelling should take the place of indoor work for at least ten days a month.

At first sight, on examining the tropical forest, it appears like a very mixed collection of different kinds of trees; on closer inspection, however, similarities and contrasts are apparent, such as Ebony, _Diospyros mespiliformis_, with its thin, black scaly bark, and that of the somewhat regularly, deeply fissured bullet-wood tree, _Mimusops multinervis_, and its white latex, which the former does not exude.

In walking through a forest, it is normally best to make the carriers precede. Owing to their tendency to lag, and their desire to sit down at inconvenient times, it is an advantage to have them in front. Frequently one may have to stop and examine a flower or leaf, and it only adds to the carriers’ labour if the whole column has to stop whilst seeds and specimens are being collected. A march of about 15 miles is sufficient, and takes up the better part of the day, if an examination of the forests is being made on the way. In most parts villages are eight to ten miles apart, sometimes nearer; so the carriers can stop and purchase food. In the larger forests, however, a distance of over 20 miles is sometimes covered without sight of a house; in that case the people of the last village are asked to bring food for the carriers, and the carriers themselves are given a day’s food as well, which has to be cooked on reaching camp. In some places the chiefs provide food (yams, etc.), which is distributed to the carriers, or in some places 3d. a day per head is allowed them for purchasing food. So long as the carrier gets food and his load is not excessively heavy, he is quite cheerful and walks well. He will pick his way in mud, over roots, and up the steepest rocks in the hill forests.

Current wages vary from 9d. to 1s. a day, the head-man getting from 1s. to 2s. a day. Local felling-permits being issued both by the District and Forest Officers to natives for felling timber for local use, at District Stations a call is paid the District Officer to discuss current forest questions and examine the permit books. At the same time there is an opportunity of seeing what further development of forest work is possible in the district. The local Forest Guards, Foresters, or Forest Rangers report themselves, usually giving a very good account of the local forest conditions. Since the demand for local timber has been growing, a stop may have to be made to supervise the marking or girdling of suitable trees for bridge-building under the auspices of the Public Works Department. On a journey through the mahogany forest, the different camps of the timber firms have to be visited. These firms have hundreds of square miles for the purpose of exploiting mahogany and furniture woods. At the same time the checking and inspecting of the stumps of all the trees felled has to be gone through. The young mahogany seedlings are also seen, and from the number of these it is known whether sufficient have been planted to take the place of those cut down. The very rapid growth of these trees can here be studied to advantage; trees now 40 feet high have only been planted a few years. The relative value of the direct planting of seedling trees as compared with the natural regeneration of the forest by self-sown seedlings can be observed with ocular clearness. In one part of the forest one sees natives standing on a platform hacking away with an axe into a huge 50-feet mahogany; in another place a similar tree, fallen, its 90-feet bole already sawn into three round logs: while in a third locality may be seen a native, axe or adze in hand, squaring mahogany logs with a 4-feet side. Later in the season eighty or more natives are engaged in dragging one of these logs on round billets of wood (for rollers) along a track, roughly cleared to the height of a man, to the nearest natural water-way; still later (that is, in July or August), when the rivers rise, the logs may be seen floating singly down to the rafting-place on the main creek, where rafts are made with logs four or eight abreast, each fastened to the next, from a timber-dog at either end, with cane. From here, riverine natives such as the Ijors take the logs to the nearest river or ocean-going steamer port.

The administrative work of the Department is in the hands of the Senior Conservators of Forests, under whom the Conservators manage their circles. The Chief Conservator of Forests, the head of the Department, initiates and controls the whole policy of the Department, being relieved of all details of administration. In order to ensure continuity of policy and action, a Working-plans Division has been formed. A working plan for the forests is a scheme of management laid down for a number of years; no change can be made in such a plan without special reference both to the head of that division and to the head of the Department. With only one year’s service, followed by leave of absence, continuity of action would be broken if it were not for a definitely approved plan.

The Forest Department has supplied the Railway, Marine, and Public Works Department with timber of various kinds. In some cases the timber is obtained by departmental working, and in others is cut by native contractors under the supervision of the Department. In the first instance, the conditions under which timber is to be supplied to other departments are put before the Secretariat, and when once the work has been begun, the local Forest Officer deals direct with the department concerned.

Forestry progress in Nigeria has been less tardy than in several other Colonies, though many forests have been destroyed owing to lapse of time before the formation of a department. In 1904 there were eight, and there are now twenty-four administrative appointments. The amalgamation of Northern and Southern Nigeria into one administration should accelerate the development of Forestry. It is as yet only in its initial stages, and scarcely more than a thousand square miles of forests, out of nearly a hundred thousand which exist in some form or another, have been permanently set aside for further timber production. The revenue- earning capacity of the Forest Department has been somewhat diminished by the war; but with recent legislation more local revenue should be obtained, which should more than off-set any loss already sustained. Provided the financial position of Nigeria remains strong, the prospects of the Forest Department are quite bright.

Although Nigeria has by far the largest Forest Department, very similar conditions of service obtain in the other West African Colonies of the Gold Coast and Sierra Leone; but there are no Forest Officers in the Gambia.

VI. A REVIEW OF THE BOTANICAL FEATURES OF NORTHERN NIGERIA.

BY DR. J. M. DALZIEL.

The Northern Provinces of Nigeria exhibit in an interesting manner the transition, now familiar in West Africa, of physical characteristics from the tropical forest to the border region “that just divides the desert from the sown.”

So far as the progressive stages may be stated in terms of geographical latitude, we may place the northern limit of the forest belt at about 8° North latitude. A convenient natural boundary in a portion of the area under consideration may be accepted in the lower course of the Benué River from its tributary, the Katsina River, or even as far up as Ibi, to the Niger at Lokoja. On the other hand, the southern limit of the desert is taken at about 17° North latitude, or higher, and thus falls some three or more degrees beyond the northern boundary.

Between these arbitrary limits lies the greater part of Northern Nigeria and practically the whole of Hausaland, presenting physical features which vary through grassy plains and rolling downs, orchard-bush and thin-crowned forest, laterite plateaux and hilly woodlands, to the mountains of the Bauchi Highlands. The vegetative covering over a very large area can be classed as one or other type of savannah, tree and bush savannah, or open orchard and treeless savannah, with intermediate grades. Local topography alters the type here and there, galleries of evergreen vegetation occupying the intersecting belts of permanent streams or fringing a marsh, wide meadows bordered by low forest, but occupied entirely by grasses of few species, with scattered islets of foliage, or, again, outcrops of bare laterite and isolated domes and turtle-backs of crystalline rock, “inselbergs” and “kopjes,” introducing features of their own.

The Niger Delta displays admirably the high evergreen or moist tropical forest. This probably connects itself through the Kameruns with the great Central African forest of French and Belgian Congo, which is again said to be continuous through the gap between Ruwenzori and Lake Albert with that of British East Africa.

West of the Niger Delta the coast, including Lagos, Dahomey and Togo, is sandy, and bush rather than high forest commences almost on the shore. Ascending the Niger, one finds that the true “rain forest” ends, but not abruptly, in the neighbourhood of Asaba; a gradual transition occurs, first to an intermediate type, partly evergreen with many large trees, but mingled with those that lose their leaves in the months of little rainfall. This change is apparent even on the river-bank, and below Lokoja a more open but still semi-evergreen forest clothes the valleys, but shows already more of the deciduous element on the hills. Farther north the voyage from the mouth of the Kaduna River to the Zungeru light railway terminus at Barijuko, as often experienced in previous years, reveals again the progressively deciduous character of the foliage, resulting in a still more open forest.

The river-bank, however, possessing permanent moisture and its own local climate, is an inadequate index of the general features over the country at large. To travel by land from Baro to Zungeru, and thence either through Kontagora to Sokoto, or by Zaria to Kano and Gummel, is to have the complete vision of the West African savannah in its various degrees, and, except for local interruptions associated with considerations of altitude or geological outcrop, etc., or with the lines of perennial streams, to have it in its regular sequence.

Leaving out of account for the present the region south of Lokoja and of the south bank of the Benué, which in part represents the “Zone Guinéenne” of Chevalier, we find that the two routes suggested above will take one through country almost entirely of the types included by the same writer within the “Zone Soudanienne,” with an approach at places along the Anglo-French boundary to the conditions occurring in his “Zone Sahélienne.” It would be difficult and misleading to express these zones definitely in terms of latitude, but one might hazard the statement that the Guinea Zone passes to the Soudan Zone somewhere between 8° and 10° North, and the latter extends either to the northern boundary or verges on a drier belt beyond the latitude of 12° or 13° North. If a complete botanical survey were possible, one could then subdivide each belt into its different areas and provinces, with their special floral characteristics, but at present one must be content to indicate broadly the general composition.

The Soudan Zone, indeed, includes the greater part of Hausaland and is representative of the typical West African savannah and savannah forest. It merges into the drier sandy “steppe” conditions in the north and into the mixed deciduous and semi-evergreen forests farther south. The only giants in height are the silk-cotton-trees (_Eriodendron orientale_), but baobabs of enormous girth are common, and the largest timber trees are probably the Maje (_Paradaniellia Oliveri_) and the Kawo (_Afzelia Africana_), fair specimens of the dry-zone mahogany, Madachi (_Khaya Senegalensis_), occurring also in favourable situations.

Across the central part of Northern Nigeria, let us say from Kontagora and South Sokoto through the whole of Zaria and South Kano to South Bornu (but excluding the Bauchi plateau, of which I cannot speak from personal knowledge), the plants named in the list here given might be regarded as the average association of species, trees, shrubs and herbaceous, the chief Natural Orders being represented as follows:

ANONACEÆ by the common wild custard apple, Gwandar daji, _Anona Senegalensis_, a shrub.

CAPPARIDACEÆ by the Ingidido, _Cratæva Adansonii_, by shrubs or woody undershrubs of genera _Boscia_ and _Mærua_, some thorny scramblers of the genus _Capparis_, and the familiar weed Gasaya, _Gynandropsis pentaphylla_.

BIXINEÆ by the Rawaya, _Cochlospermum tinctorium_, a shrub.

HYPERICINEÆ by the shrub Kaskawami, _Psorospermum Senegalense_.

OCHNACEÆ by the Namijin kade, _Lophira alata_, a tree very typical of the region, two or three species of _Gomphia_, and a new species of _Ochna_, a small shrub with crenulate leaves.

MALVACEÆ by numerous species of _Hibiscus_, including the cultivated Rama (chiefly _K. cannabinus_) and Cotton, with the Ramaniya, _Urena lobata_, and various undershrubs and suffrutescent weeds, mostly of the genus _Sida_. The Kuka or baobab, _Adansonia digitata_, and the Rimi or Silk-cotton Tree, _Eriodendron orientale_, marking the sites of human habitations, past or present, are typical species of this area, as is also the red-flowered Gurjiya, _Bombax buonopozense_ (Bombacaceæ).

STERCULIACEÆ by the Kukuki, _Sterculia tomentosa_, a tree, with which we may place the common undershrub Hankufa, _Waltheria Americana_.

TILIACEÆ by several species of _Grewia_, the most familiar being the Dargaza, _G. mollis_, by two or three species of _Corchorus_, edible herbs allied to jute, and by shrubby weeds of the genus _Triumfetta_.

SIMARUBACEÆ by _Hannoa undulata_, a small-sized tree characteristic of the region, and by _Irvingia Smithii_, a tree more abundant in the South.

BURSERACEÆ by two species of frankincense-tree—_Boswellia Dalzielii_ and _B. odorata_—and by _Commiphora Kerstingii_, a green-barked tree familiar as an enclosure fence in towns.

MELIACEÆ by _Khaya Senegalensis_, the mahogany of the Soudan Zone, by _Trichilia emetica_, and by _Pseudocedrela Kotschyii_; also by the naturalized Kurnan nasara, _Melia Azedarach_.

OLACACEÆ by the Tsada, _Ximenia Americana_, a shrub with small yellow, acid plums, and by the evergreen climbing shrub, _Opilia celtidifolia_.

CELASTRACEÆ typically by the shrub _Gymnosporia Senegalensis_, and less by two or more species of woody twining _Hippocrates_.

SAPINDACEÆ by the woody twiner _Paullinia pinnata_, the 3-foliate shrub _Schmidelia Africana_, and the world-wide twining weed _Cardiospermum Halicacabum_.

ANACARDIACEÆ by the tree _Odina Barteri_, by other species of _Odina_ of more local distribution, and by two species of _Anaphrenium_.

CONNARACEÆ by the abundant little shrub _Byrsocarpus coccineus_.

PROTEACEÆ by a single species of _Protea_, a shrub with large capitate flowers, of local distribution in the Central areas.

POLYGALACEÆ by _Securidaca longipedunculata_ and the field weed _Polygala arenaria_.

LEGUMINOSÆ by—

Larger trees: the Maji or Kadaura, _Paradaniellia Oliveri_, and the Kawo, _Afzelia Africana_.

Medium-sized and smaller trees: _Parkia filicoidea_, _Prosopis oblonga_, _Pterocarpus erinaceus_, _Isoberlinia doka_, _Berlinia acuminata_ in ravines, _Tamarindus Indica_; several Acacias, e.g. _A. Sieberiana_, _A. campylacantha_, _A. Arabica_; _Albizzia Chevalieri_, _Entada Sudanica_; _Afrormosia laxiflora_ and _Burkea Africana_.

Small trees and shrubs: _Detarium Senegalense_, _Bauhinia reticulata_ and _B. rufescens_, _Erythrina Senegalensis_, _Lonchocarpus laxiflorus_, _Dichrostachys nutans_, _Mimosa asperata_ on stream-banks, _Cassia Sieberiana_, _C. Kotschyana_ and others, along with several shrubby species of _Cassia_ and the dwarf _C. mimosoides_, _Swartzia Madagascariensis_, _Ormocarpum bibracteatum_.

To these must be added the Zamarke, _Sesbania punctata_, and other _spp._, and a host of herbaceous plants or half woody undershrubs, chiefly belonging to the genera _Crotalaria_, _Indigofera_, and _Tephrosia_, others of _Desmodium_, _Eriosema_, etc., and twiners of _Vigna_ and _Rhynchosia_.

The chief cultivated Leguminosæ of the region are: Indigo, _Indigofera arrecta_ and other _spp._, _Arachis hypogæa_, _Vigna sinensis_ in numerous varieties, and _Voandzeia subterranea_.

ROSACEÆ mainly by _Parinarium curatellæfolium_, to which may be added _P. polyandrum_ in the South and _P. macrophyllum_ in the North.

COMBRETACEÆ by several species of _Terminalia_, of which the commonest are the Baushe (of more than one species) and the Kandari, _T. macroptera_; more fully by a number of species of _Combretum_, which are trees often gum-yielding, and very typically by the Marike, _Anogeissus leiocarpus_.

MYRTACEÆ by _Eugenia Owariensis_, a tree, and _E. coronata_, a shrub.

LYTHRACEÆ by the “henna” shrub, _Lawsonia alba_, and the weed of damp places, _Ammannia Senegalensis_.

ARALIACEÆ by an interesting species, _Cussonia Nigerica_, a small tree of peculiar habit.

RUBIACEÆ by _Adina microcephala_, a fair-sized tree by bush streams; by very numerous small trees and shrubs, e.g. _Crossopteryx Kotschyana_, _Sarcocephalus Russegeri_, _Pavetta Barteri_, _Feretia canthioides_, the _Gardenia erubescens_ and the Gauden kura, _G. ternifolia_, the Giyaiya, _Mitragyne Africana_, typical of the islets of foliage clothing the grassy swamps, _Morelia Senegalensis_ on stream-banks, and by more humble but abundant species of _Oldenlandia_, _Spermacoce_, _Octodon_, etc.

SAPOTACEÆ by the Shea Butter Tree, _Butyrospermum Parkii_, probably the most characteristic member of the association.

EBENACEÆ by the African Ebony, _Diospyros mespiliformis_.

APOCYNACEÆ typically by the arrow-poison woody climber _Strophanthus sarmentosus_, which is always wild, and _S. hispidus_, which is generally planted near villages—both species called Kwankwanni; also by the more common and inferior rubber vine, _Landolphia florida_, and shrubs _Carissa edulis_ and _Cryptolepis Nigritiana_, the woody twiners _Tacazzea Barteri_ and other _spp._, with numerous others.

ASCLEPIADACEÆ by the very typical giant milkweed Tumfafiya, _Calotropis procera_, probably always in association with man, the smaller undershrub _Asclepias lineolata_, and several suffrutescent herbs with tuberous and sometimes edible rootstocks of the genera _Xysmalobium_ and _Schizoglossum_.

LOGANIACEÆ by _Strychnos spinosa_, _S. alnifolia_, and _S. triclisioides_, all shrubs or small trees.

BORAGINACEÆ by _Cordia Abyssinica_, a small tree, the undershrub _Trichodesma Africanum_, three or four weeds of the genus _Heliotropium_, etc.

BIGNONIACEÆ by _Stereospermum Kunthianum_, a small tree, and the Aduruku, _Newbouldia lævis_, confined to towns and rarely more than a tall, slender shrub; the Rahaina or Rawuya, _Kigelia Æthiopica_, occurs, but in an interrupted distribution.

VERBENACEÆ by _Vitex Cienkowskii_, a fair-sized tree, _V. diversifolia_, a small tree or shrub, and undershrubs such as _Lantana salvifolia_, _Lippia Ukambensis_, and a few species of _Clerodendron_, etc.

EUPHORBIACEÆ by _Uapaca Guineense_, usually only a rather small tree in the deciduous forest, _Bridelia ferruginea_ and _B. scleroneura_, both shrubs, _Phyllanthus floribundus_, forming sometimes thicket-like clumps, _P. reticulatus_, a shrub, _Flueggea microcarpa_, a white- berried shrub, _Antidesma venosum_, and very typically by the Jan yaro, _Hymenocardia acida_, a shrub which in these open regions has nearly always an ochre-red bark. Numerous herbs and half-woody weeds are common, belonging to the genus _Euphorbia_ (_E. pilulifera_, _E. Ægyptiaca_, and congeners), _Acalypha_, _Phyllanthus_, etc., the Castor Oil shrub (_Ricinus communis_) and the Physic Nut (_Jatropha curcas_) are cultivated, while thoroughly representative through the whole area are the familiar cactus-like Tinya, _Euphorbia unispina_ and _E. Poissoni_, and the Kerana, _E. Barteri_, the latter at least never away from habitations.

MORACEÆ by a host of species of the genus _Ficus_ (or _Urostigma_) not yet fully elaborated botanically, e.g. Baure, Chediya, Durumi, Kauriri, Wa, etc.

ULMACEÆ. A representative variety is _Celtis integrifolia_, a fairly large tree.

SALICACEÆ by one species of _Salix_.

LORANTHACEÆ by seven or eight species of the parasite _Loranthus_, called Kauchi, clothing deciduous trees with epiphytic foliage.

Orders represented mainly by flowering herbs, undershrubs, etc., are:

MENISPERMACEÆ by the popular medicinal twiner Jibda kassa, _Cissampelos Pareira_.

NYMPHEACEÆ by at least four species of Bada or water-lily, _Nymphæa_.

PAPAVERACEÆ by the Yellow Poppy, _Argemone Mexicana_.

CARYOPHYLLACEÆ by species of _Polycarpæa_ characteristic of the dry zone.

GERANIACEÆ by the familiar weed _Biophytum sensitivum_.

DROSERACEÆ by the widely distributed Sun-dew, _Drosera indica_.

AMPELIDEÆ by numerous vines of the genera _Vitis_, _Cissus_, and _Ampelocissus_, of which perhaps the most striking are Dodoriya, _Vitis quadrangularis_, and Dafara, _Vitis pallida_, while wild vines with edible berries called Tsiberi kinkini are generally of one or other species of _Ampelocissus_.

CUCURBITACEÆ by the familiar cultivated Kabeova or pumpkin, _Cucurbita Pepo_, and Duma, the bottle-gourd, _Lagenaria vulgaris_, with its endless varieties, the Guna or water-melon, _Citrullus vulgaris_, and by many wild and half-wild species, e.g. the Balsam Apple, _Momordica balsamina_, the Loofah gourd, _Luffa Ægyptiaca_ and _L. acutangula_, _Cucumis prophetarum_, and one or more species of tuberous-rooted _Trochomeria_.

FICOIDEÆ by common succulent weeds, e.g. _Trianthema monogyna_, _T. pentandra_, and _Gisekia pharnaceoides_, and by species of _Mollugo_ in river-beds, etc.

COMPOSITÆ by some weeds of cosmopolitan distribution, e.g. _Ageratum conyzoides_, _Eclipta alba_, etc., and by very numerous herbs and suffrutescent plants, amongst which the genus _Vernonia_ is the most abundantly represented, including one typical of the region, viz. _V. nigritiana_, with several species of _Aspillia_, _Coreopsis_, etc., and the chewstick shrub, _Vernonia amygdalina_.

MELASTOMACEÆ by a few species of _Dissotis_ and _Osbeckia_.

CAMPANULACEÆ by a common little blue-flowered weed, _Cephalostigma Perrottetii_, and a water herb, _Sphenoclea Zeylanica_.

HYDROPHYLLACEÆ by three or more species of _Hydrolea_, e.g. _H. Guineensis_, etc.

LENTIBULACEÆ by ten or more species of _Utricularia_.

CONVOLVULACEÆ, a conspicuous order, well represented by numerous species of _Ipomæa_, a few of _Merremia_, and a few erect undershrubs of the genus _Astrochlæna_, to which one may add the little blue-flowered weed _Evolvulus alsinoides_, of wide distribution in the world.

SOLANACEÆ by the “Thorn Apple,” _Datura Metel_, by numerous species of _Solanum_, some edible, e.g. the several cultivated varieties of the native bitter tomato, Gauta, varieties of _S. Melongena_; others poisonous, e.g. Gautan kura, _Solanum incanum_, and others; also by two common weeds of the genus _Physalis_, and the popular herb simple, Dandana, _Schwenkia Americana_.

SCROPHULARIACEÆ by _Scoparia dulcis_, of world-wide distribution, and by several parasitic species of _Striga_, of which the most familiar is the Makasar adwa, _S. Senegalensis_. Besides numerous humble weeds of cosmopolitan genera, e.g. _Moniera_, _Ilysanthes_, etc., mostly occurring in damp places, two or three species of _Sopubia_ may be taken as characteristic of the bush-lands.

ACANTHACEÆ by a variety of weeds, etc., of the genera _Blepharis_, _Monechma_, _Justicia_, etc., to which the following may be added as characteristic of the Order in Hausaland: _Nelsonia campestris_, a soft herb of slightly acid taste, _Peristrophe bicalyculata_, an occasional fodder plant, and _Dyschoriste Perrottetii_, the mucilaginous seeds of which are used to remove spicules from the eye.

PEDALIACEÆ by the locally cultivated Ridi, _Sesamum Indicum_, and other wild species of _Sesamum_, by the weed _Ceratotheca sesamoides_, and by the half-shrubby _Rogeria adenophylla_.

LABIATÆ by several cultivated tubers, such as the Tumuku and Risga, by odorous species of _Ocimum_ and _Æolanthus_, e.g. the Dodoya, _Ocimum Americanum_, the weed _Acrocephalus polytrichus_, and by many common herbs of various other genera.

AMARANTHACEÆ by the native spinage, Alayafu, _Amaranthus caudatus_, the Zaki banza, _A. viridis_, a wild species sometimes cultivated, and by several of the common weeds found in other countries—_Celosia argentea_, _Pupalia lappacea_, etc.

THYMELÆACEÆ by the poisonous Tururibi, _Lasiosyphon Kraussii_, a yellow- flowered, low, suffruticose plant with a woody rootstock, and by two of three species of _Gnidia_.

ARISTOLOCHIACEÆ by the twiner _Aristolochia albida_.

LAURACEÆ by the leafless twiner _Cassytha Guineensis_.

The Monocotyledonous Orders may be said to be represented as follows:

HYDROCHARITACEÆ by the yellow-flowered aquatic herbs _Ottelia lancifolia_ and _Boottia Abyssinica_.

ORCHIDACEÆ by a fair number of tuberous terrestrial orchids, of which _Lissochilus arenarius_ is the most typical, several _Habenarias_ and _Eulophias_, and a very few epiphytes, e.g. _Ansellia Congoensis_.

SCITAMINEÆ abundantly by _Kœmpferia Æthiopica_ in open woods, _Costus afer_ in shady ravines, and Fitta, the food-wrapper leaf, _Clinogyne filipes_, in streams, etc.

IRIDACEÆ by several species of _Gladiolus_, e.g. _G. quartinianus_, and of _Tritonia_.

AMARYLLIDACEÆ by _Crinum yuccæflorum_, the red-flowered _Hæmanthus rupestris_, _Pancratium trianthum_, and _Curculigo Gallabatensis_.

TACCACEÆ by the tuberous _Tacca involucrata_.

DIOSCOREACEÆ by _Dioscorea prehensilis_ and other cultivated yams, chiefly in the South or on pagan hills, and by some species which are either wild or escapes.

LILIACEÆ by several species of _Urginea_, e.g. _U. Nigritiana_, _U. Indica_, etc., by other bulbous species of the genera _Anthericum_, _Dipcadi_, etc., by the climbing lily, _Gloriosa superba_, several species of _Chlorophytum_, _Aloe Barteri_, and by prickly scramblers such as _Asparagus Pauli-Guilelmi_, _Smilax Kraussiana_, etc.

ALISMATACEÆ by some flowering water-plants, e.g. _Burnatia enneandra_, _Lophotocarpus Guyanensis_, etc.

COMMELINACEÆ by various species of _Aneilema_—_A. lanceolatum_, _A. Sinicum_, etc., of _Commelyna_—_C. nudiflora_, _C. umbellata_, etc., and of _Floscopa_ and _Cyanotis_.

PALMÆ by the Giginya, _Borassus flabellifer_, var. _Æthiopum_, the Goriba, _Hyphæne Thebaica_, chiefly in the North, and the Tukuruwa or Bamboo Palm, _Raphia vinifera_, in ravines only.

AROIDEÆ by _Culcasia scandens_, by the Kinchia with yellow rhizome, _Stylochiton Dalzielii_, _Amorphophallus Barteri_ and _A. dracontioides_, _Anchomanes Dalzielii_, and other species.

CYPERACEÆ by very numerous species of _Cyperus_, e.g. the edible Aya, _C. esculentus_, and the uncultivated Aya aya, _C. rotundus_, _C. Fenzelianus_, etc., and several of _Pycreus_, _Fimbristylis_, _Kyllingia_, _Bulbostylis_, etc.

GRAMINEÆ by the predominant tribe, _Andropogoneæ_, with numerous other genera—_Eragrostis_, _Aristida_, _Digitaria_, _Pennisetum_, _Chloris_, etc., and by a single locally distributed bamboo, _Oxytenanthera Abyssinica_. The chief cereal is Guinea Corn, Dawa, _Sorghum vulgare_; both species of sugar-cane, Rake, _Saccharum officinarum_, and Takanda, _Sorghum vulgare_, var. _saccharatum_, are cultivated.

The FILICES are poorly represented by the widely distributed Adder’s Tongue, _Ophioglossum vulgatum_, the water-fern, _Cratopteris Thalictroides_, by _Adiantum lunulatum_, _A. Schweinfurthii_, and a few species of _Nephrodium asplenium_, etc., by no means typical of the region.

Having thus given a bird’s-eye view of the floral composition in the central region of Hausaland, one may proceed to examine the variations revealed in passing south to the semi-evergreen forests and north to the drier open savannahs.

Southwards the transition is gradual, and nowhere abrupt, from forest savannah with annual bush-fires and consequent tendency to revert to grass, to forests in which the number of species is greater and the deciduous element is more mingled with evergreens, either by the persistence of species which in a drier region are deciduous, but retain their foliage where the increased rainfall allows of this variation, or by the appearance of species which always possess the evergreen habit. _Bombax buonopozense_ is an example of the former and probably also _Afzelia Africana_ and several others.

Some of the added constituents either absent from or more rare in the area of lesser rainfall are:

ANONACEÆ: _Xylopia parviflora_, _Hexalobus Senegalensis_, _Popowia Mannii_.

CAPPARIDACEÆ: _Ritchiea sp._, _Capparis viminea_, etc.

BIXINEÆ: _Oncoba spinosa_.

STERCULIACEÆ: _Cola laurifolia_.

RUTACEÆ: the Fasa kwari, _Zanthoxylum Senegalense_.

MELIACEÆ: _Trichilia retusa_.

ANACARDIACEÆ: _Spondias lutea_, _Hæmatostaphis Barteri_, and the cultivated mango.

SAPINDACEÆ: _Blighia sapida_.

CONNARACEÆ: scrambling shrubs, e.g. species of _Agelæa_ and _Cnestis_.

To face p. 196.

LEGUMINOSÆ: _Tetrapleura Thonningii_, _Piptadenia Africana_, _Erythrophlœum Guineense_, _Cynometra Vogelii_, _Pterocarpus esculentus_, _Dialium Guineense_, _Millettia sp._ near _M. Sanagana_ and other species of _Millettia_, _Cordyla Africana_, _Berlinia Heudelotii_, _Cæsalpinia Bonducella_, _Lonchocarpus cyanescens_, _Baphia pubescens_ and _B. nitida_.

ROSACEÆ: _Parinarium subcordatum_.

COMBRETACEÆ: several species of scarlet-flowered _Combretum_ of climbing habit—_C. racemosum_, _C. constrictum_, etc.

MYRTACEÆ: _Napoleona Vogelii_.

RUBIACEÆ: _Morinda citrifolia_, _Cuviera acutiflora_, _Canthium Vanguerioides_, _Ixora radiata_, _Uncaria Africana_, _Oxyanthus unilocularis_, some species of _Mussænda_, etc.

RHIZOPHORACEÆ: _Weihea Africana_.

SAPOTACEÆ: _Mimusops sp._

APOCYNACEÆ: _Voacanga obtusa_ and _V. Africana_, _Landolphia Owariensis_ and other _spp._, _Carpodinus hirsuta_, _Pleioceras Barteri_, and the tree Wadda, _Rauwolfia sp._ near _R. Welwitschii_.

LOGANIACEÆ: _Anthocleista Vogelii_.

CONVOLVULACEÆ: _Calonyction speciosum_, _Merremia umbellata_, etc.

BIGNONIACEÆ: _Spathodea campanulata_.

ACANTHACEÆ: _Acanthus montanus_, _Asystasia Coromandeliana_, etc.

VERBENACEÆ: _Vitex chrysocarpa_ and _V. Angolensis_.

PIPERACEÆ: _Piper umbellatum_ and _Piperomia pellucida_.

GESNERACEÆ: _Streptocarpus nobilis_.

EUPHORBIACEÆ: _Alchornea cordata_, _Mallotus oppositifolius_.

MORACEÆ: _Chlorophora excelsa_, _Ficus Vogelii_ and other _spp._, _Myrianthus serratus_.

ULMACEÆ: _Trema Guineensis_.

AMPELIDEÆ: _Leea Guineensis_.

POLYGALACEÆ: the cultivated _Polygala butyracea_ and the dwarf species, _P. Clarkeana_.

BALANOPHORACEÆ: the root-parasite _Thonningia sanguinea_.

Amongst Monocotyledonous Orders the _Scitamineæ_ are more in evidence, _Palisota thyrsiflora_ (_Commelinaceæ_) appears (along with a _Begonia_ on moist rocks—_B. rostrata_), and the water-loving Aroid, _Cyrtosperma Senegalense_.

The Oil Palm, _Elæis Guineensis_, becomes locally common, ferns become epiphytic, and the Elk’s-horn fern, _Platycerium Æthiopicum_, appears.

Northwards the savannah forests, with plenty of broad-leaved trees and shrubs, or the open park-like formations with surface well covered with grasses and herbs, give way in some places to still drier Acacia forests, and in others to open areas of scrub, nearly treeless, the soil possessed by grasses and low, scattered shrubs, often thorny. Nevertheless, 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.

CAPPARIDACEÆ: most of the species of _Capparis_, _Boscia_ and _Mærua_ existing farther south here prevail; the low shrub _Boscia Senegalensis_ is common, while _Cadaba farinosa_ is a characteristic shrub.

SIMARUBEÆ: the Aduwa, _Balanites Ægyptiaca_, is a typical species of this region.

BURSERACEÆ: the Dashi, _Balsamodendron Africanum_, a shrub yielding African Myrrh, is familiar, with its congener _B. pedunculatum_.

RHAMNACEÆ: 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.

ANACARDIACEÆ: the Danya, _Spondias sp._, a fair-sized tree with yellow, plum-like fruit having a leathery rind, is abundant.

LEGUMINOSÆ: Acacias are the most typical, but are not as a rule markedly flat-topped, e.g. _A. Seyal_, _A. Senegal_, _A. albida_ var. _saccharata_, _Dichrostachys platycarpa_, forming thorny thickets, while _Entada Sudanica_, _Acacia Sieberiana_, _A. campylacantha_, _Albizzia Chevalieri_ and others are also evident. _Parkinsonia aculeata_ is found in towns; the Tripoli or Senegal Senna, Filasko, _Cassia obovata_, is common, and the Tsamiya, _Tamarindus Indica_, becomes a predominant tree.

ROSACEÆ: the Ginger-bread Plum, Gawasa, _Parinarium macrophyllum_, is more familiar.

COMBRETACEÆ: the Geza, _Combretum sp._ near _C. altum_, a shrub or small tree, with several gum-yielding trees of the same genus; the low shrub Sabarra, _Guiera Senegalensis_, is perhaps the most typical plant of the nearly treeless savannah.

CUCURBITACEÆ: the half-wild Gurji, _Cucumis Melo_, var. _agrestis_, is common, and the Bambus, a variety of water-melon, is known in the North.

RUBIACEÆ: a characteristic species is _Randia Nilotica_, a thorny shrub; _Gardenia Sokotensis_ is a new species found on low rocky hills.

APOCYNACEÆ: the Kariya, _Adenium Honghel_, an unarmed cactus-like shrub, deciduous, with rose-coloured flowers, planted in towns, is characteristic.

ASCLEPIADACEÆ: the small milk-weed, _Glossonema Nubicum_, and the twiners _Oxystelma Bornuense_, _Pergularia tomentosa_ and _Leptadenia lancifolia_, are all abundant, while the Karan masallachi, _Caralluma Dalzielii_, generally planted farther south, is found wild on bare rocky places.

EUPHORBIACEÆ: very typical are the two milk hedge Euphorbias, Aguwa, _E. sepium_, and Fidda sartsi, _E. lateriflora_.

MORACEÆ: species of _Ficus_ planted for shade grow to a large size, especially the Chediya, _F. Thonningii_, and the Durumi, _F. syringifolia_; other species generally start as epiphytes.

The GRAMINEÆ is the prevailing Natural Order of Monocotyledons, and includes all types—little annuals, perennial-rooted _Andropogons_, etc., and the Burugu, _Panicum stagninum_, which blocks the streams. The fragrant Nobe, _Cymbopogon Sennariensis_, is a characteristic tufted species, whilst the bur-grass Karangia, _Cenchrus catharticus_, has long since spread far southward.

Rice and wheat are cultivated; the Bulrush Millet, Gero, _Pennisetum typhoideum_, tends to displace _Sorghum_, and a wild rice, _Oryza silvestris_, is found. The cultivated sugar-cane is the Takanda, _Sorghum vulgare_, var. _saccharatum_.

Of LILIACEÆ the onion and garlic are features of cultivation. Several bulbous herbs not peculiar to the North are common, e.g. _Dipcadi occidentale_, _Urginea spp._, etc.

The Goriba or Dum Palm, _Hyphæne Thebaica_, is predominant, accompanied also by the Giginya or Deleb Palm, while the Date begins to appear.

Within the limits of the Soudan Zone of vegetation many different types of savannah may be found, besides the expected alterations in botanical groupings resulting from the presence of perennial moisture or due to elevation and rocky outcrop. Leaving the latter out of account, a few notes may be made of some of the varieties familiar to travellers in the Northern Provinces.

1. _Tree Savannah or Savannah Forest_.

Across a considerable area of Central Hausaland, e.g. occupying a large part of the Zaria plateau west of the Bauchi Highlands, the country, where not cleared for farming, is covered with an open deciduous forest of fair height. This is a fairly closely wooded type, and although it contains few truly evergreen elements apart from those lining the streams, there is, perhaps owing to differing vegetative periods for different species and to the double flowering season noted for many trees in West Africa, practically always a fair amount of foliage present. A proportion of the trees have well developed stems and fairly high crowns, with a leafy canopy which filters but never excludes direct sunlight, and the average height of the larger trees is from 30 to 40 feet. In the best developed portions of such forest the grasses do not predominate, but frequent clearings or patches of stony outcrop lead to the open conditions in which hardy perennial grasses take root, and annual burning results in the encroachment and multiplication of areas of the lower bush savannah referred to below.

This variety of forest is typically seen in Zaria province, e.g. between the village of Ruka and the Koriga stream, near which point a sudden drop in elevation occurs, and is familiar in parts of South Sokoto, Kontagora and Nassarawa, etc. _Lophira alata_ has its chief habitat here, but perhaps the prevailing and most characteristic tree is one called Doka, which has been identified as _Isoberlinia doka_, Craib, et Stapf. It has broad, shining leaves, and large, flat 5-6 seeded pods which dehisce with curling valves. It seeds abundantly, and young seedlings spring up quickly in the forest or by wayside clearings, etc. Along with it will be found its congener, the Fara doka, _Isoberlinia Dalzielii_, Craib, et Stapf., less abundant, and differing as to its more obvious features in having leaves not shining, a paler grey bark and a general slight degree of pubescence of all parts. Both species exude a coarse red resin, which does not appear to be of value.

Most of the arborescent species mentioned in the list of the average association detailed above are to be found, sometimes harbouring epiphytic _Ansellias_ and a few woody climbers but no typical lianes, and an undergrowth composed of Leguminous and Composite herbs and undershrubs with some grasses. This type of forest probably at one time covered a much wider area and had a greater extension northward than at present. As mentioned above, a large proportion of its constituents may again be found in the Duru forest between Sokoto and Kano, while within the memory of officials of the present administration areas of woodland previously visible from Sokoto have been denuded for firewood. It tends progressively to give place to the following more open variety of savannah.

2. _Bush Savannah_.

This is probably the form of “bush” with which travelling officials, hunters, and others are most familiar in every province, and is, when not overloaded with tall grass, deserving of the term “open orchard savannah.” It is composed of scattered shrubs and small trees of short growth and of a considerable sameness, the whole picture being practically filled in with grasses, which may grow to a height of 6 to 8 feet in the rains, but which are swept off by bush-fires in the dry period, leaving bare the intervening spaces, soon to be reoccupied by suffrutescent plants with persistent rootstocks, and later by weeds and the same grasses as before. This resurrection is not due to seeding, which is itself abundant, but mainly to the fact that the majority of bush grasses have perennial underground stems, which, once given occupation, are difficult to dislodge, and, assisted by the recurrent fires, which kill off the seeds and the seedlings of broad-leaved trees, have everything in favour of their natural progress to predominance.

The commoner bush grasses of this habit found here are: _Andropogon Gayanus_, _Cymbopogon Ruprechtii_, _C. diplandrus_, _C. giganteum_, _C. hirtus_, _C. rufus_, _Andropogon tectorum_, _A. apricus_, _Rottbœllia exaltata_, _Pennisetum pedicellatum_, etc. In clumps, generally found in special situations, e.g. near river banks, etc., are _Vetiveria zizanoides_, _Saccharum spontaneum_, _Arundo donax_, etc. It is possible that some of these species which now cumber the soil might be put to use in supplying the raw material for paper.

The prevailing shrubs and small trees of this formation are generally somewhat as follows: _Bauhinia reticulata_ and _B. rufescens_, _Detarium Senegalense_, several species of _Combretum_ with the dwarf _C. herbaceum_; also _Afrormosia laxiflora_ and occasional _Acacias_, e.g. _A. Sieberiana_, _Entada Sudanica_, _Dichrostachys nutans_; bright flowering species, such as _Cochlospermum tinctorium_; several shrubby species of _Hibiscus_; _Cassia Arereh_, _C. Goratensis_ and other species, _Lonchocarpus laxiflorus_, _Securidaca longipedunculata_, _Grewia mollis_, _Feretia canthioides_; the _Gardenias_—_G. ternifolia_, _G. erubescens_, etc.; _Stereospermum Kunthianum_, _Sarcocephalus Russegeri_, _Parinarium curatellæfolium_, _Psorospermum Senegalense_, _Ximenia Americana_, _Anona Senegalensis_, _Pseudocedrela Kotschyi_, _Strychnos spinosa_ and other _spp._, _Bridelia ferruginea_, _Hymenocardia acida_, _Gymnosporia Senegalensis_. Occasional larger trees will often be species of _Terminalia_, _Prosopis oblonga_, _Butyrospermum Parkii_, _Lophira alata_, _Vitex Cienkowskii_, _Sterculia tomentosa_, _Pterocarpus erinaceus_, or even _Afzelia Africana_ and _Paradaniellia Oliveri_.

In the above association remark must be made of the Taura, _Detarium Senegalense_, which is here rarely of dimensions meriting the designation of tree, and therefore very different from the large timber known in the southern forests and found also on the forested slopes of Patti at Lokoja; of the Makarfo, a tree of twisted habit, not often over 30 feet high, with flaking bark, apparently much inferior to the _Afrormosia laxiflora_, if it is this species, in the greater mixed deciduous forests farther south; and of the Tsada, _Ximenia Americana_, which is here unarmed, has rather thin, glabrous leaves, sometimes almost shining, and thus differs in habit from the coastal variety, if the identity is certain, which is spiny, has dull leaves sometimes half- succulent, and is appropriately called by the French “Citron de la mer.”

3. _Park Savannah._

The open park-like formation is another which is typical of this region. It is, perhaps, best seen where the population is not quite sparse, as in the latter case the previous type tends to take possession. The Shea Butter Tree is the one which more than any other gives the tone to this type, but _Parkia filicoidea_ and, especially in the North, the Tamarind are perhaps equally representative. The two first-named, though not necessarily indicating the proximity of a village, have probably in most cases owners, and the intervening spaces may or may not be more or less cultivated. Open park-like country may, however, occur apart from any contemporary interference by man, and wide stretches of it appear alternating with scattered orchard bush or with open grass-land. The grasses are of the previously mentioned types, with many species of _Eragrostis_, _Aristida_, small annual tufted grasses and sedges, along with _Cassia mimosoides_, _Oldenlandia grandiflora_, _O. Senegalensis_ and other Leguminous and Rubiaceous weeds. Other trees which well maintain the park-like appearance are _Terminalia macroptera_, occasional species of _Ficus_, _Vitex Cienkowskii_, _Acacia Arabica_ and _A. Sieberiana_.

In flat, wide-stretching meadows which are often marshy in the rains, this formation also maintains its character, single trees or island-like clusters of tree and shrub dotting the expanse of heavy grass which is burnt to desolation by the yearly fires. These islets are generally found to be composed of Giyaiya, _Mitragyne Africana_, with shrubs such as _Feretia canthioides_, _Sarcocephalus Russegeri_, and scrambling undershrubs added thereto, while the edge of such a meadow or “fadama” is in some cases fringed with deciduous high woods, in which occasionally timbers like _Khaya Senegalensis_ and _Paradaniellia Oliveri_ may appear along with the vegetation characteristic of Type 1.

4. _Evergreen Fringing Belts._

Along the water-courses which intersect the savannah lands will be found dark evergreen strips of foliage, which, when extending beyond the stream-banks and forming a fairly dense canopy, whatever the nature of the underwood, are generally implied in the Hausa word “kurumi.” The streams may not be always truly perennial, but the verdure remains because the moisture in the soil persists long enough to maintain the non-deciduous type, although bush-fires may reach their very margins. Where a perennial stream of any magnitude occurs, species will be found whose distribution in the Soudan Zone is confined to such localities, but which are widely represented in the South.

Instead of enumerating the constituents of these strips of fringing forest, we may briefly refer to the vegetation of the River Benué, which has been already indicated as in some degree marking the boundary between the semi-evergreen or mixed deciduous forests and the drier tree savannah and open bush lands. The evergreen galleries along the streams or fringing the swampy glades may be taken as on the whole botanically similar to the bank foliage of the Benué and its backwaters, creeks and tributaries. One feature of this type is the abundance of woody climbers, often concealing the foliage of their supports, and conspicuous to the eye in the flowering season are the _Combretaceæ_, which are here scrambling and climbing shrubs instead of erect trees, e.g. the flame-flowered _Combretum racemosum_, _C. constrictum_, etc., _Quisqualis Indica_ and others; also two or three species of _Landolphia_ with other rubber vines, and of _Mussænda_, scarlet-fruited _Connaraceæ_, _Uncaria Africana_, climbing by its old flower-stalks becoming woody hooks, and _Alchornea cordata_, the most typical liane of these formations. Other twiners are the showy moon-convolvulus, _Calonyction speciosum_ (_Ipomæa bona-nox_), the Cowhage, _Mucuna pruriensis_, _Dioclea reflexa_, _Entada scandens_ and numerous _Ampelideæ_. These tend to form a dense and sometimes impenetrable tangle, but where trees of timber size occur the undergrowth is more scanty and a variety of forest weeds appear, in which the _Scitamineæ_ may be prominent.

The Benué region is rich in trees, of which the following species may be mentioned: Goron ruwa, _Irvingia Smithii_, and Gedar kurumi, _Pterocarpus esculentus_, _Trichilia retusa_, the large timber tree called Kiriyar kurumi (undetermined), _Erythrophlœum Guineense_, _Millettia sp._, _Sanagana_ and _M. sericeus_, _Cynometra Vogelii_, _Anthocleista nobilis_, _Berlinia Heudelotii_, _Baphia nitida_, _Chlorophora excelsa_, _Cola laurifolia_, _Parinarium subcordatum_, _Kigelia Æthiopica_, _Uapaca Guineensis_ (here a large tree and sometimes prop-rooted), _Ficus spp._ Smaller trees and shrubs are: _Spathodea campanulata_, _Voacanga obtusa_ and _V. Africana_, _Morinda citrifolia_, _Xylopia parviflora_, _Zanthoxylum Senegalense_, _Oncoba spinosa_, _Vangueria euonymoides_, _Ixora radiata_, _Polysphæria macrostyla_, _Garcinia ovalifolia_, _Myrianthus serratus_, _Elæis Guineensis_ and _Raphia vinifera_. Not all of these extend far beyond the Benué, but the majority of them will be found in one or other fringing belt far into the deciduous region, and perhaps the two which best represent this extension of the semi-evergreen to the savannah are the woody climber _Alchornea cordata_ and the tree _Irvingia Smithii_.

In a general view, Northern Nigeria, thus lying beyond the equatorial belt, possesses plant features which, apart from river and stream fringes, range between the mixed deciduous and xerophilous habit, and in the dry season the prevailing character of the open savannah forests is a monotonous drab or grey, intersected by the dark lines of greenery following the streams or encircling the swamps. The climate is largely of the continental type, with a temperature ranging from 120° F. to 40° or less (exclusive of thermometer readings on the Bauchi plateau), and a rainfall which throughout will usually fall between 30 and 50 or 60 inches, with diminution to 20 or even 10 inches in the most northerly provinces. Such a climate, with the concomitant regularity of two, not four, well marked seasons, the dry and the wet, is entirely that associated with the occurrence of savannah formations, scattered bush with prevailing grasses, suffrutescent herbs and small trees, much open grass or thinly timbered park-land, with stretches of thick woods which are generally not heavily grassed and never cumbered with impenetrable undergrowth.

Trees which are valuable timber species in the moist southern forests often scarcely attain reputable dimensions in the deciduous zone.

These conditions also, which are doubtless partly the result of ill- considered human operations, put certain definite restrictions on cultivated species and determine the character of the natural products of the wild. The staple cereal is Dawa or _Sorghum_, instead of maize, with Gero or _Pennisetum typhoideum_ in the North. Possibly the limit of Guinea Corn as a staple of native cultivation is also the limit of the savannah forests, i.e. of the region of trees of secondary size, short of the region of Acacias, of Geza, _Combretum altum_, and of scrub, where Bulrush Millet is the commoner. Both species are generally cultivated along with beans, _Vigna Sinensis_. The sweet potato displaces the yam and cassava; industrial cultivation is represented by cotton and indigo. Of forest products, the most representative are Shea nuts and gum arabic, rather than rubber and large timber; and lastly, both cattle-grazing and horse-breeding are important industries proper to the region.

VII. SOME TREES OF HAUSALAND.

BY DR. J. M. DALZIEL.

A few notes on some of the better known trees of Northern Nigeria are here given, the Hausa name being appended in most cases.

_Afrormosia laxiflora_, Harms (Leguminosæ). Makarfo.

In the mixed deciduous forests towards the coast this appears as a large timber tree, in certain regions dominant both in abundance and size, and is also a constituent of the moist evergreen forests. In Northern Nigeria it never forms a straight stem, never attains the dimensions of a timber tree, and has generally a twisted stem and main branches. Its habit, therefore, rather than its mere presence, affords a striking instance of the changes accompanying the limited rainfall of the savannah forests, and its distribution probably does not extend beyond the northern boundary. The trunk has a somewhat pale piebald appearance, resulting from the flaking of large pieces of the bark exposing lighter portions below. The centre wood is so dark in colour as to have led European foremen of works to report it as lignum vitæ, and the wood is hard enough to earn for it in some districts, along with other trees, the designation “break axe.” It has shining leaves, whitish flowers and thin, flat pods.

_Afzelia Africana_, Sm. Kawo; “African” or “Rhodesian” Mahogany, “Mahogany Bean,” etc.

A large tree, common to nearly all types of forest in West Africa, tropical high forest, mixed deciduous and savannah. In Northern Nigeria large specimens may still be found, though these do not generally have tall, straight stems, but show the wide-spreading umbrella crown common in drier regions.

_Paradaniellia Oliveri_, Rolfe. Kadaura or Maje.

This has previously been classed with _Daniellia thurifera_, Bennett, the so-called West African Copaiba Balsam Tree.

In the Northern Provinces of Nigeria it is one of the largest trees, 50 to 80 feet, with strong, straight stems and affording good timber for local use. The chief native use of the oleo resin is to fumigate garments. Its distribution probably stops short of the northern boundary.

_Isoberlinia doka_, Craib, et Stapf. Doka.

A tree which is the prevailing type in the savannah forests of Central Hausaland, generally 30 to 40 feet high, with broad, shining leaves, rather small white flowers and large flat pods containing five or six discoid seeds. The valves of the pods curl up after dehiscence, and young seedlings spring up vigorously where not choked by grass, farm clearings in Zaria province being often quickly occupied by them.

A coarse red resin exudes from injuries or punctures of the bark.

_Isoberlinia Dalzielii_, Craib et Stapf. Fara doka.

Another new species of similar occurrence and habit, differing in having a more grey appearance associated with a slight pubescence, leaves not shining and pods less smooth. A species of the wild silkworm, _Anaphe Moloneyi_, and perhaps others, are found on them.

_Pterocarpus erinaceus_, Poir. Madobia; “Senegal Rosewood,” “African Kino,” etc.

A tree generally of 30 to 40 feet or more in open savannah forests, easily recognized by its bright yellow flowers, the regular venation of the leaves, and the bristly, flat, one-seeded pods. The blood-red resin is a variety of Kino, and in districts where the Camwood is not found, the bark of Madobia is sometimes sold as a substitute. The wood is hard and fine-grained.

_Cassia Sieberiana_, DC. and C.; _Kotschyana_, Oliv. Marga or Gamafada.

These are small trees with conspicuous yellow flower racemes, having a superficial resemblance to laburnum. They are abundant in the dry savannah regions as well as in savannah forest, and flower freely in the dry season. The pods are long and cylindrical and do not dehisce. _Cassia Arereh_, Del., is similar, but the leaves are more acuminated and the pods split up longitudinally.

_Detarium Senegalense_, Gmel. Taura.

A good timber tree in the mixed deciduous and higher savannah forests, as also in the mountainous peninsula of Sierra Leone. Fairly large specimens of timber dimensions occur in the rocky forest overlooking Lokoja, but the Hausa Taura, hitherto identified as botanically the same, is of a very different habit, abundantly represented in the open bush savannah as a shrub or small tree having somewhat flattened fruits, oval, less succulent than, and one-half or one-third the size of, those shed by the forest specimens.

_Tamarindus Indica_, Zinn. Tsamiya; “Tamarind Tree.”

A very familiar tree in the northern Hausa States and Bornu, as well as in French territory to the north, but much less common on parts of the border-line between Southern and Northern Nigeria, so that probably its actual distribution is local and interrupted. Barth places its limit at Tagalel, in Damerghu, or about 15° North latitude.

In Hausaland it is a conspicuous tree, less from its dimensions than from the beauty of its foliage, sometimes umbrella-spreading and at others compact, and giving a good deal of shade when in full leaf. The ground becomes littered with the small leaflets in the dry months, and as a rule little undergrowth is to be found beneath it.

In Sokoto and Kano provinces, and elsewhere in the North, specimens with a dense, compact and symmetrical crown are common, the branches often reaching to within 3 or 4 feet of the ground. The fruit has familiar medicinal and culinary uses, but rarely develops the soft rich pulp of the Indian specimens. One of the wild silkworms, _Anaphe sp._, feeds on the leaf, the silken nest being called “Tsamiyar Tsamiya.” A familiar association which did not escape the notice of Dr. Barth is that of tamarind and baobab, in which case the former is often without a proper bole and spreads itself half scandent amongst the stout branches of the baobab.

_Parkia filicoidea_, Welw. Dorowa; “West African Locust Bean.”

A characteristic tree of the savannah forests, and one of the most typical members of the open park-like formations. It appears to be scarce in Bornu, but abundant from Zaria to Katsina, and its northern limit is probably about 14° North latitude.

The pods afford both food and fodder, the fermented cakes called Daudawa, made from the seeds, being an article of local commerce. In the bush, far from villages, Dorowa trees are ownerless, but elsewhere they are generally private property.