22 



shifting system of farming. The following are the commonest trees 

 found in this farm belt : — 



Alchornea cordifolia. Pandanus candelabrum. 



Bomhax sp. Pentaclethra macrophylla. 



Conoplmryngia Jollyana. Piptadenia africana. 



Elceis guineensis. Pycnanthus Kombo. 



Musanga Smithii. Terminalia sp. 



Myrianthus arbor eus. Triplochiton Johnsoni. 



Fresh Water Marshes. — Wherever any depressions exist sufficient 

 to retain the surface water or wherever the presence of an abundant 

 supply of water in the subsoil is evident, a marshy flora occurs which, 

 except in the case of some of the herbs, is distinct from the true aquatic 

 flora. The soil is chiefly sand or mud washed down by the rain and 

 accumulated often to a considerable depth. 



As a rule big trees are at intervals, and consequently there is no 

 canopy of trees ; the smaller trees also, such as Mitragyne macrophylla, 

 and the species of Macrolobium, occur isolated. The characteristic 

 species of the formation are the Palmacece, both arboreal and scandent, 

 and they are to be seen at their optimum. The armed species of 

 Calamus and Ancistrophyllum throw their loops over everything, 

 binding the shrub vegetation together and making travelling through 

 the bush very difficult. Around the edges of these marshes, but 

 included within them are also found the massive loops of the Landolphia 

 lianes and akin genera, which here seem also to reach their optimum. 

 In the wettest localities the majority of arboreal species are charac- 

 terised by pneumatophores, which may be anything up to two feet 

 in height. 



Of the herbaceous climbers and flora the Aracece. and Scitaminece 

 form the greater part and frequently dominate the community to the 

 absence even of the Palmacece, and in tliese cases pure societies of a 

 single species are a characteristic feature. 



Along the river banks the same formation occurs. Here, however, 

 there is often in addition a fringe of an aquatic formation, but this, 

 except in the case of a few Cyperacea, is distinct. Even where partial 

 submersion occurs during the rains the vegetation is quite distinct 

 from the aquatic formation which exists only in free water. 



In this group also are the societies of herbs which form so distinctive 

 a character of this type of marsh. Of these the commonest are of the 

 AracecB, Anchomanes duhius, Anuhias Afzelii, and Cyrtosperma sene- 

 galense : of the Scitaminece, Amomum Granum-Paradisii, and a 

 species near A . Melegueia, Calathea conferta, Clinogyne fiexuosa, and 

 Phrynium brachystachyum. 



The River Banks. — Where the influence of the water of the river is 

 appreciable in the subsoil of its banks a marsh type of flora is very 



