47 



Apocynaceae. 



The genus Landolphia include several valuable species, 

 the most important being L. ftorida (Vahea comorensis) L. 

 ovariensis (white rubber vine) and L. Kirkii from East 

 tropical Africa. 



Other species are:— L. Thpllonii, Southern Congo, L. 

 Buchananii, East tropical Africa, L. petersiana, Trop 

 Africa, L. senegalensis, and L. tomentosa, W. Coast, L. 

 madagascariensis, East Coast, The Landolphias possibly 

 occur all over tropical Africa including Madagascar and 

 Zanzibar. All are climbing plants resembling the Malayan 

 Willughbeias and require a post or other tree to support 

 the vine or liane and consequently are not of easy cul- 

 tivation. The supply of rubber from indigenous plants 

 owing to excessive and uncontrolled tapping — has con- 

 siderably diminished. In German East Africa more con- 

 trol is excercised and worked areas are stated to be closed 

 for a period of 3 or 4 years after tapping. Plantations, too, 

 are being formed at the Botanic stations of British African 

 possessions but it is doubtful if these can do more than 

 reserve seeds. 



So far, only dirty, badly prepared rubber has been put 

 on the market from Africa and some of this loses as much 

 as 50% weight in washing. In some parts of Africa the 

 native collectors allow the latex to flow on the ground, 

 where some of the moisture is adsorbed or evaporated and 

 when coagulated is afterwards gathered regardless of dirt. 

 In other parts the negroes smear the latex over their 

 bodies and when sufficiently agglutinated, tear it off and 

 roll into balls. From the Congo some Landolphia rubber 

 is obtained by diluting the latex with water and as the 

 caoutchouc separates it is skimmed off and kneaded into 

 various forms, while at other places on the West Coast 

 rubber is prepared by treating the latex with salt-water, 

 lime juice or boiling effusions of certain plants, notably 

 Bauhinia reticulata. As may be inferred much of such 

 rubber is very poor grade and only obtains a low price. 

 Some of the best prepared Mozambique ball (probably — 

 Landolphia Kirkii) reached 4/9^ against 5/4 for fine hard 

 Para, 



Funtumia elastica (Lagos silk rubber) was first re- 

 ported from Lagos in 1894. It is widely distributed on the 

 West Coast and is also abundant in Uganda. Unlike the 

 climbing Landolphias — to which Funtumia is allied— this 

 species forms a medium sized tree and admits of easy cul- 



