JULV I, 1905] 



THE INDIA RUBBER WORLD 



335 



THE "GUAYULE" RUBBER PLANT~1. 



Vy Rudolf l-.ndlu It. I'll. D* 



WITHIN the confines of the rej^lons in whicli the plant 

 grows in Mexico, Guayule rubber has been known 

 for a long lime. In some parts of the country, and 

 especially in the state of Durango. toy balls have 

 from times immemorial been made by cliewinj; Guayule bark. 

 The first reports concerning this plant and the rubber derived 

 therefrom are said to have been made by a certain Negrete (?), 

 a Jesuit priest, as far back as the middle of the eighteenth cen- 

 tury. 



The Guayule. or Huayle (Partlifnium ari^enlatum, A. Gray), 

 a dwarf tree belonging to the order of the Composilu-, varies in 

 height between .20 and i meter (average height about .60 

 meter). The trunk has a gray bark and spreads out into many 

 branches. At the ends of the branches, which are often knot- 

 ted, the reproduction shoots are de- 

 veloped, and bear leaves provided with 

 stems, partly lancet shaped with even 

 edges, and partly serrated with rounded 

 indentations. They are silver gray in 

 color, 2 to 4 cm. in length and from .3 

 to I cm. in width, and form a bushy or 

 umbrella shaped crown. The plain, 

 yellowish buds are atli.xed to compara- 

 tively long stems (ranging in length up 

 to 20 cm.). The plant blossoms during 

 the months of September and October. 

 The large number of young plants 

 sometimes found surrounding the older 

 trees make it probable that the Guay- 

 ule can be easily reproduced by means 

 of its seed, provided conditions are 

 somewhat favorable. In the territory 

 surrounding Jimulco, for instance, as 

 many as 50 young plants have been 

 found around full grown trees. Condi- 

 tions for the development of the young 

 plants, however, are often very unfav- 

 orable, especially in very hard and 

 rocky soil, where it is ditTicult for the 

 shoots to take root. This is probably 

 the reason why young plants are sel- 

 dom found in the territory surround- 

 ing old mines, where in former years 

 Guayule wood, on account of its excel- 

 lent heating capacity, was used as fuel 

 for ore roasting and for bakers' ovens. 



The fact, however, that some young plants are found even in 

 such unfavorable spots, makes it likely that they have been de- 

 veloped from such seeds as were either stamped into the ground 

 by goats (as these animals are the ones which commonly graze 

 in the Guayule territories), or had been dropped by these ani- 

 mals, and thus found favorable conditions of development in 

 the animal excrements. It would, in fact, beditlicult to find any 

 other explanation for the enormous growth of the Guayule 

 plant in small, isolated places (having usually the size of the 

 resting places of the goat herds), as such accumulations of Guay- 

 ule plants would otherwise be found in the lowest places at 



*Trans)ated for Thk India kuimi:R World from Der 'rroJ>inpjlanzer (Berlin), 

 IX Jahrg., Nr. 5. t Phoiographed for The India Rubber World. 



THE GUAYULE PLANT. + 



times covered by surface water if the seeds had been carried 

 along by the rainfall. 



In some districts, such as the territory surrounding Saltillo, 

 it is said that the goats are doing considerable damage to the 

 development of the Guayule by frequently feeding on the leaves 

 of the young shoots. That these animals, however, should die 

 by eating Guayule leaves appears very unlikely. Land owners 

 and managers had not observed any such results, although the 

 knotted ends of the branches showed that the leaves and repro- 

 duction shoots of the Guayule plants growing on their lands 

 had often been gnawed by goats. 



The general opinion is that the Guayule gradually commences 

 to die ofT after a life of about 15 years. The stumps of trees 

 that have been cut down are said to soon sprout again and to 

 produce, after a lapse of several years, 

 new plants ready for cutting. How long 

 the time is that must elapse appears to 

 be still unknown. As the Guayule 

 loots, however, break easily when the 

 trunk is cut down, most gatherers pre- 

 fer to pull out the stronger parts of the 

 roots along with the trunk. 



The name Guayule (guayhule) or 

 Huayule is probably derived from the 

 Spanish word Hay ("there is") and 

 from the Indian word HuU, meaning 

 India-rubber. Besides this the plant 

 is known by several other names. In 

 the state o( Durango (in the neighbor- 

 hood of Pasaje), for instance, it is called 

 " yerba de hule," in the north of Zaca- 

 tecas "hule," in the northern parts of 

 San Luis Potosi "yule," and in the 

 Saltillo territory " jiguhite " (meaning 

 weed). In a few places it is known as 

 " copalin." 



The other names "mariola" and 

 " yerba del negro " mentioned by W. 

 Prampolini in his patent specification 

 are evidently the result of misinforma- 

 tion, for in the states of Durango, Coa- 

 huila. Chihuahua, Zacatecas, in the 

 Federal district, etc., another species 

 of Parthenium (Parthenium incanum, 

 H. B. K.), similar to the Guayule, is 

 known under the name of " mariola " 

 and is a popular remedy for stomachal diseases. The Sphec- 

 ralcea atti^ustifoiia, St. Hilaire, of the natural order Malvacea, 

 used as an emollient, is known in many parts of Mexico as 

 " yerba del negro." 



The Guayule Is found in a comparatively large part of the 

 "bush prairies " {chafiarraUs) in the northern part of the Mex- 

 ican highlands. The total supply, however, as well as the ex- 

 tent of the territory in which the plant grows, has been consid- 

 erably overestimated. It seems that the principal cause of 

 this overestimation is due to the " mariola " (Parthenium in- 

 canum), which is found in the same territories as the Guayule, 

 but in vastly greater numbers. This connection is furthermore 

 proved by the fact that specimens of Parthenium incanum have 



