295 



sam£ year. An abstract of this was published by Dr. R. Endlich 

 of Mexico, and the notes given below on the tree and the rubber 

 production from it are taken from this article. 



Unfortunately the name Euphorbia elastica was, a few months 

 previously, viz., in April of the same year, given by Professor 

 Jumelle to a totally different species of Euphorbia, a native of 

 Madagascar. The Mexican plant had therefore to receive a new 

 name and, as "Amarillo" corresponds to the Latin "fulvus," I 

 propose for it the name Euphorbia fulva. 



Euphorbia fulva is a tree 8-10 metres high, with a yellow, 

 smooth, shining bark ; hence the name Palo Amarillot, that is 

 " yellow tree." It occurs in the States of Michoacan, Guanajuato, 

 Jalisco, and in the western parts of the State of Mexico, usually 

 at an altitude of 1500-1900 m. The annual rainfall of that area 

 is between 550 and 750 mm., and the mean annual temperature 

 between 17° and 20° C. (62'5°-68°F). The tree thrives well also 

 on stony or rocky soil. Attempts to produce rubber from its 

 latex were made in Michoacan some time ago, but given up as no 

 process was known to separate the rubber from the resin, which 

 occur in the proportion of 18-20 per cent, and 40 per cent, 

 respectively. Recently, however, Professor Lozano succeeded in 

 separating completely the two substances and producing very 

 good rubber, according to some, even better than " caucho negro 

 (Central American rubber), and, from the resin, an excellent 

 varnish. The process of separation has, however, so far not been 

 made public, and at the time when the article was written the 

 whole matter was still in the experimental stage, although plans 

 for working the Palo Amarillo in Michoacan were under consider- 

 ation. Since then an application for a concession to establish 

 and work factories for the extraction of rubber from the tree in 

 the States of Guerrero, Jalisco, Michoacan, Guanajuato, Oaxaca, 

 Puebla, Lower California, Colima, and the Territory of Tepic has 

 been made by Senor Carlos Llaguna y del Hoyo, of Michoacan.* 



The latex of Palo Amarillo is yellowish white, thin, and does 

 not coagulate readily. To effect this it is exposed to the sun It 

 not subjected to Lozano's process the product is dark yellow, 

 dough-like and neither resilient nor viscous. If boiled the latex turns 

 very sticky and whitish grey. Experimental tapping in Guanajuato 

 and Michoacan resulted in an average yield of 1 lit. (I'/o pmi; 

 of latex per tree. It is recommended to proceed with the tapping 



downwards 



tapping is done judiciously the tree may be rea dy for an other 

 yield after three months, and it is expected that it will sand 

 three tappings per annum for 10 years. In Atecucano hatchets or 

 « machetes " (large knives) are used, and the incisions are made in 

 an oblique direction parallel to each other, or in spirals The 

 latex is collected in petroleum cans or smal pots. Am tain 

 portion coagulates on th^ree^andjsjemove d with knives. It 



* Der Tropenpflanzer, 1906, pp. 525-531. „;„nata Lae Olahonia 



t The name Palo Amarillo is also applied to ?^' l" nn *% ^Wats and 



pinnata, Fedde), and to two species of Boccoma viz -B. arborea, Y\ats., ana 



B.frutescens, Linn.— See Ramirez, Sinon. Plant. Uex. Pt in • . . dpamtch ^ the 



X Diario Oficial, dated March 8th. 1907, according *™^™ l £^£^ 



Foreign Office by Mr. R. Tosver, Envoy Extraordinary and Minister Plenipotentiary, 



Mexico, dated March 1 2th, 1907. 



