360 



LORANTHUS AS A PARASITE ON HEVEA 

 BRASILiENSIS. 



A short time ago the Acting Conservator of Forests wrote to 

 the Director of Agriculture stating that on a recent visit to Pahang 

 he noticed many Para Rubber trees at Pekan affected by a parasitic 

 growth of some kind, similar to mistletoe. The parasite was not 

 confined to Para rubber, but other trees, among which Casuarinas 

 and Mangosteens were noticed, were very badly attacked. Specimens 

 were obtained and it was found that the parasite was a species of 

 LoranfJius. The particular species could not be determined owing to 

 the condition of the material. It is quite possible that the parasite 

 may be found on rubber trees in other districts, and a short account 

 of it may therefore be interesting to planters. 



Loranthus is closely related to the European mistletoe. There 

 are man^^ species, and they are all parasitic on trees, mostly in the 

 tropics. The plants attach themselves to the branches of trees and 

 form shrubby growths, often of a considerable size. The leaves are 

 green, and usually of a leathery texture. Like all plants with green 

 leaves, L^?rrt«.'/jM5 can manufacture its ow^n carbonaceous food, and it 

 probably draws little more from the host-plant than supplies of 

 water with the salts dissolved in it. It is therefore not a true para- 

 site, for these derive all their nutriment from the plants on which 

 they live, and on accounts of its partial independence it is called a 

 semi-parasite. 



The mode of distribution is peculiar and interesting. Each 

 fruit contains a large seed, around which is a layer of a very viscid 

 substance. The fruits are eaten by birds, which are fond of the 

 pulpy fruit-coat. The seeds, however, are not eaten, ether because 

 the sticky substance makes them difficult to swallow, or because 

 they are distasteful on account of the large amount of tannin they 

 contain. The bird gets rid of the seed by rubbing its bill against 

 some convenient object, usually the branch of a tree. Here the seed 

 adheres and germinates. The seedling puts out a root-like organ, 

 and if the tree happens to be a suitable host it penetrates the bark 

 and bores its way down to the wood. After a time lateral " roots " 

 are put off from this primary " root " and grow along the branch 

 between the wood and the bark. Buds arise from the upper side of 

 those lateral "roots," push their way outwards, emerge and from 

 -new branches. A shrub-like growth ultimately results. 



As a rule a species of Loranthus will not grow on any and every 

 kind of tree, but has a preference for certain kinds. Some species are 

 more , indiscriminate than others, and it is not at all surprising that 

 ohe'of them should have taken a liking to Hevea. In other tropical 

 countries Loratithus attacks various plants of economic importance. 

 For mail}' years it has been a troublesome parasite on tea in India 

 Burma and Ceylon. 



