Botanical Position of the “Ofruntum” Tree.—The “Ofruntum,” or African rubber, is botanically placed in the Natural Order Apocynaceæ, under the specific name of Funtumia elastica, Stapf. Until recently it was referred to as Kicksia africana, Benth. and others (a genus which is not known to occur in West Africa), and it was also confused with a very nearly allied species, occurring in the same localities, and now known as Funtumia africana, Stapf. Owing to the great similarity which these species of Funtumia bear to one another, it is important that the differences between them should be recognised, F. africana not furnishing any but very inferior rubber. The most reliable method of testing the species which produces rubber, is by rubbing a small quantity of latex between the finger and thumb, when small particles of rubber should be quickly formed, the latex of F. africana becoming only a sticky mass under the operation. The leaf of F. elastica can usually be recognised by the presence of a small pit at the origin of each secondary nerve or vein on the under-surface, which feature is not characteristic of the leaf of F. africana, although recently individual trees have been found exhibiting this peculiarity. The flower bud of F. elastica is typically much shorter than that of F. africana, and the double seed pod of the former species is shorter and more blunt than that of the latter.
Distribution of F. elastica.—The Funtumia rubber tree occurs in a wild state in the forests throughout the Gold Coast and Ashanti, although it has been nearly exterminated in some parts. It appears to be most plentiful in the dense forest regions of Northern Ashanti.
Native Methods for Preparing.—Funtumia rubber is exported under the names of “Ashanti lump” and “Niggers,” which consist of much adulterated, evil-smelling substances, for which a low price is procurable in comparison with that paid for pure rubber. In certain years the demand for this has been maintained, but the adequate supplies of good rubber from elsewhere, and the rapid expansion of the cocoa industry, have caused a diminution in the export of native-made rubber, which has been replaced to a small extent by plantation rubber.
The wild trees grow from 50 to 100 feet in height, and often have a girth of three feet at four feet from the base; the trunk being commonly without branches for a considerable height. The native ascends the trunk by means of a sling passed round it, to one end of which is a loop which fits over his right thigh and to the other a stirrup in which he keeps his left foot. By moving the rope up the tree the ascent is quickly accomplished, and when stationary, both hands are left free. The climber carries a gouge, or semi-cylindrically-faced chisel, with which he cuts vertical as well as transverse oblique grooves, forming a rough “herring-bone” pattern, which may be continued for the whole length of the trunk, and even extend on to the main branches. To make the cuts the tool is either used in one hand or is held in the left and driven by blows on the end of the handle, given with the palm of the right hand. The flow of latex commences at once, and is directed down the vertical channel into a calabash placed at the base of the tree, into which the latex is guided by a lip of clay or a chip of wood. The illustration shows a native in Ashanti tapping a tree ([Fig. 18]). The quantity of latex procured at the one tapping varies; an exceptionally large amount being about two quarts from a large tree. The tree is not tapped again for several months and until the wounds have healed. On the second tapping the same form of cuts is made upon the opposite side of the tree, and the transverse channels often intersect those made previously; besides this, owing to the want of regulation in the depth of the cuts, the inner or cambium layer of the bark may be so damaged that the intersecting cuts may ring the tree and cause death. Few trees probably survive the third or fourth tapping.
“ODUM” TREES CHLOROPHORA EXCELSA.
Fig. 19, [p. 72.]
PARA RUBBER TREE (HEVEA BRASILIENSIS), TAPPED AT ABURI.
Fig. 20, [p. 66.]