THE AFRICAN RUBBER VINES 187 



Landolphia chi/lcnrhiza, Stapf ; Clitandra henriquesiana, 

 K. Schum. ; and Carpodinus gracilis, Stapf. 



Attention may again be drawn to the fact that a 

 considerable number of Apocynaceoiis vines contain 

 latex which does not yield rubber, but only a resinous 

 product, so that it is necessary to discriminate between 

 the useful and the worthless species. Some of the vines 

 which do not fm'nish rubber, e.g. Landolphia florida, 

 Benth., are very widely distributed throughout tropical 

 Africa. 



The rubber plants belonging to this group occur over 

 practically the whole of Central Africa and in Madagascar, 

 their limit in the north extending from Senegambia to 

 Abyssinia, and in the south from Portuguese West Africa 

 to Zululand. In many districts within this area rubber 

 vines were formerly extremely abundant, and the greater 

 part of the wild rubber produced in Africa is still derived 

 from them. 



Botanical Characters. — The three genera Landolphia, 

 Clitandra, and Carpodinus belong to the same tribe of 

 the natiural order Apocynaceae and are very closely related. 

 The majority of the species are woody climbers, many of 

 which attain a very large size. The climbing is effected 

 by means of strong hook-branched tendrils which may 

 be either terminal or axillary. In some cases, however, 

 the plants are dwarf shrubs or undershrubs which have 

 partly herbaceous branches or throw up fresh shoots 

 annually, and certain species which occur normally as 

 vines in the forests develop a bushy habit when growing 

 upon open ground where there are no trees to serve as 

 supports. 



The leaves are simple, opposite, and vary considerably 

 in size in the different species. The flowers are salver- 

 shaped, resembling jasmine, and are usually sweet 

 scented ; they are arranged in terminal or axillary cymes 

 which may be few- or manj^-flowered. In some cases 

 the flowers are of considerable size and are produced 

 very profusely in large, compact clusters. The fruit 

 is a rounded or pear-shaped berry, varying from less 

 than 1 in. to 10 in. in diameter, and is often brightly 

 coloured ; the fruits are frequently eaten by the natives. 

 The seeds are either iew or many, and are embedded 

 in the juicy pulp of the fruit. 



