THE 



Transactions 



OF 



The Royal Society of South Australia. 



Vol. XL. 



a note on the occurrence and method of 

 Formation of the Resin (Yacca Gum) in 

 Xanthorrhoea Quadrangulata. 



By Professor T. G. B. Osboen, M.Sc. 



[Read April 13, 1916.] 



Plates I. to III. 



References to the utilization of the resin of Xanthorrhoea 

 species (the Australian ''Grass Tree"), commonly known as 

 "Yacca Gum," as a source of picric acid, in addition to its 

 value as a varnish, are to be found in various encyclopaedic 

 works. 0) In September last the Faculty of Science of the 

 University of Adelaide was asked by the Hon. the Minister 

 of Agriculture to investigate the matter further, with, amongst 

 other things, a view to the more profitable working of the 

 natural supplies existing in parts of this State, especially on 

 Kangaroo Island. The majority of the questions asked were 

 upon chemical points, but some referred to the possibility of 

 methods of harvesting the resin other than that at present in 

 vogue, which involves a destruction of the grass trees. 



It was necessary, therefore, to enquire into the way in 

 which the resin is formed by the plant, but upon consulting 

 the literature available ( 2 ) no definite information could be 

 obtained. An examination of specimens of one of the species, 

 Xanthorrhoea quadratic) via ta, was made, and the method of 



(i) Watts: "Dictionary of Chemistry" ; Maiden, J. H. : "The 

 Useful Native Plants of Australia," p. 231. 1889. 



(2)1 have not been able to consult — Tschirch : "Angewandte 

 Pflanzenanatomie" : Wiesner : "Die Rohstoffe des Pflanzenreiches." 

 B 



