PLANTS CULTIVATED FOR THEIE STEMS OR LEAVES. 133 



To sum up, C. olitonus seems to be wild in the mode- 

 rately waim regions of Western India, of Kordofan, and 

 probably of some intermediate countries. It must have 

 spread from the coast of Timor, and as far as Northern 

 Australia, into Africa and towards Anatolia, in the wake 

 of a cultivation not perhaps oi earlier date than the 

 Christian era, even at its origin. 



In spite of the assertions made in various works, the 

 cultivation of this plant is rarely indicated in America. 

 I note, however, on Grisebach's authority,^ that it has 

 become naturalized in Jamaica from gardens, as often 

 happens in the case of cultivated annuals. 



Sumach. — Rhus coriaria. 



This tree is cultivated in Spain and Italy ^ for the 

 young shoots and leaves, which are dried and made into 

 a powder for tanning. I recently saw a plantation in 

 Sicily, of which the product was exported to America. 

 As oak-bark becomes more rare and substances for tan- 

 ning are more in demand, it is probable that this cultiva- 

 tion will spread ; all the more that it is suitable to sandy, 

 sterile regions. In Algeria, Australia, at the Cape, and 

 in the Argentine Republic, it might be introduced with 

 advantage;* Ancient peoples used the slightly acid fruits 

 as a seasoning, and the custom has lingered here and 

 there ; but I find no proof that they cultivated the 

 species. 



It grows wild in the Canaries and in Madeira, in 

 the Mediterranean region and in the neighbourhood of 

 the Black Sea, preferring dry and stony ground. In 

 Asia its area extends as far as the south of the Cau- 

 casus, the Caspian Sea, and Persia,* The species is 

 so common that it may have been in use before it was 

 cultivated. 



» Grisebach, Fl. of Brit. West Ind., p. 97. 



* Bosc, Diet. d'Agric., at the word " STimao." 



' The conditions and methods of the caltnre of the Enmach are the 

 subject of an important paper by Inzenga, translated in the Bull. 

 Soc. d'AccUm., Feb. 1877. In the Trans. Bot. Soc. of Edinburgh, ix.p. 341, 

 may be seen an extract from an earlier paper by the author on the same 

 subject. 



• Ledebour, Fl. Ross., i. p. 509 ; Boissier, M. Orient., ii. p. 4. 



