OTHER RUBBER-YIELDING PLANTS 495 



unlike a turnip in form, native of the treeless grass tracts or 

 plateaus of Zambesi, British Central Africa, etc. It is found chieHy 

 at elevations of 4,000 to 5,000 feet above sea-level, and is consider- 

 ed one of the most important of root-rubbers, the tuberous rhizomes 

 containing a large percentage of rubber, which is extracted by 

 rasping and boiling the rhizomes. Propagated by tubers. So far 

 probably no one has succeeded in germinating seed of this plant 

 outside its native country. 



Jelutong. A glutinous resinous substance obtained from the 

 latex of species of Dyer a (chiefly D. costulata) and Alstonia large 

 trees, indigenous to Borneo, Sumatra, and Malaya. To obtain the 

 latex the trees are tapped, generally once a week, in a similar 

 method to the tapping of Hevea, the latex being coagulated by 

 adding a little kerosine oil, or sometimes other mixtures. A large 

 tree is said to yield about 100 Ib. of latex per annum. The latex 

 contains about 10% of rubber, the rest being water, resin and 

 other solids. 



OTHER RUBBER-YIELDING PLANTS 



[Many of these afford only a small proportion or an inferior quality of rubber]. 

 Actinella Richardsonii. (Apocyitacctic). Colorado Rubber. 

 Anodendron paniculata. (Apocynaceae). Large liane of Ceylon, India, etc. 

 Bleekrodea tonkinensis. (Urticaceae). Tonkin rubber. A sub-tropical tree of 



Cochin China. 

 Carpodinus lanceolata. (Apocynaceae). Root-rubber. African climber, with large 



tuberous roots. 



Clitandra Henriquesiana. (Apocynaceae). Root-rubber. An erect shrub of Cent- 

 ral Africa. 

 Cryptostegia grandiflora. (Asclepiadeac). An ornamental climber, native of 



tropical Africa; commonly grown in gardens for its large showy pink 



flowers. 



Cryptostegia madagascariensis. " Lombiri " or Madagascar rubber. 

 Ecdysanthera glandulifera. (Apocynaceae). A climber of Cambodia. 

 Eucomia ulmoides. Chinese Rubber. A bushy tree of China, suited to a cool or 



temperate climate. 

 Euphorbia rhipsaloides. (Euphorbiaceac). "Almeidina" or "Potato-gum." A 



kind of rubber obtained from a small succulent tree in Portuguese East 



Africa, whence it is exported ; it fetches 6d to 9d per Ib. in London 



(March 1913). 

 Ficus Vogleii. (Urticaceae). West African, Congo or Memleku Rubber. A 



medium-si/ed tree, introduced at Peradeniya in 1881. 

 Forsteronia floribunda. (Apocynaceae). "Milk-vine" of Jamaica. 

 F. graciiis. A liane of British Guiana. 

 Hancornia speciosa. (Apocynaceae). Mangabeira Rubber. Small shrubby tree ; 



fruit edible, seed of short vitality. 



