8 



NEIV RUBBER-PRODUCING PLANT. 



The following are a few particulars by the Chief of the Botanic 

 Section of the "Secretaria del Formento" in Mexico, printed in 

 the Bulletin of Agricultural Intelligence and of Plant Diseases for 

 September, 1912, regarding a new rubber plant. This tree, un- 

 like others, grows in hilly country in dry and stony soils. It is 

 called by the natives "Cacaloxochitl" and belongs to the genus 

 Plnmcria of the family Apocynaceae. All the known species of 

 this family in Madagascar produce a latex-like juice; but Pln- 

 meria rubra is the only one known up to now as a producer of 

 rubber in sufficient quantity to be worth extracting. 



The trunk, from 6^-16 feet high, has a girth of from 8 to 24 

 inches ; the bark is rough and of a light gray color ; the leaves are 

 opposite ; the flowers are white and large and the root is used by 

 the natives i;s a purgative. Plmneria is common in many regions 

 of Mexico and Central America ; it grows under the best con- 

 ditions in sandy, stony and rocky soils on the mountains at a 

 height of 1000 to 4000 feet, in dry regions where there is an 

 average yearly rainfall between 30 and 50 inches. 



The following composition w'as found on analyzing the coagu- 

 late of the latex : 



Resin 21.9% 



Moisture \S.7% 



Rubber 25.5% 



This tree is easily reproduced by slips, and in the Botanical Sta- 

 tion of Tezonapa, four weeks after a branch had been planted, 

 new leaflets were observed. This plant is capable of producing 

 a good quality of rubber. Investigations are being made, and 

 from the experiments carried out at the Botanical Station of Te- 

 zonapa indications are already available as to the best method of 

 tapping. The ordinary system of incision would not give good 

 results. The young parts of the plant contain a quantity of rub- 

 ber in excess of that of the trunk. Lopping off the heads of the 

 plant is advi.sable and extraction must be made from branches thus 

 pruned ; this pruning improves the condition of the tree and in- 

 creases the growth of tlu- branches. 



