94 ACACIA SENEGAL 



about half way down into 5 narrow-triangular acute segments, 

 downy. Corolla usually gamopetalous, campanulate, about twice 

 the length of the calyx, divided nearly half way down into 5 

 acute segments, white. Stamens very numerous, filaments 

 slender, erect, about 3 times the length of the corolla, yellowish, 

 united at the very base into a very short perigynous tube inserted 

 on the base of the corolla, anthers very small, roundish. Ovary 

 shortly stalked, very small, oblong, style terminal, filiform, shorter 

 than the stamens, stigma terminal. Pod shortly stalked, 3 or 4 

 inches long by about f wide, more or less constricted between the 

 2 6 seeds, flat except over the seeds, smooth, pale, membranous, 

 with a strong fibrous marginal rib and fainter transverse reticulat- 

 ing veins. Seeds with a long funicle slightly dilated at the 

 hilum, roundish in outline, very much compressed, marked on the 

 centre with a concave arched line, brown, embryo with large 

 circular plane-convex cotyledons and a -small, blunt, slightly 

 exserted radicle, no endosperm. 



Habitat. This species of Acacia, as indicated by its name, is a 

 native of Senegal in West Tropical Africa, where it covers exten- 

 sive tracts of sandy ground; it is also found abundantly on the 

 other side of the continent in the countries bordering the Upper 

 Nile, Southern Nubia, Atbara, and especially Kordofan, all in the 

 tropics. The same species appears to occur in Scinde ; whether 

 it grows also in Arabia is not known. 



From the explorations of the African traveller, Schweinfurth, 

 there is no doubt that it is from this species that the best 

 " gum arabic " is obtained in Nile-land. The gum exudes 

 spontaneously from the branches and is readily detached; it is 

 brought down the river into Egypt, from which country it is 

 exported. 



In Senegal, also, the gum of this plant has long been collected, 

 but Adanson in 1788 was the first to properly describe the tree 

 from which it is obtained. At the present time it is collected 

 exclusively by the Moors in woods mainly composed of the tree on 

 the right bank of the river Senegal, opposite the French ports of 

 Dagana, Podor, Matam, &c. It is found to exude principally 



