540 MEDICAL BOTANY. 



name of Rhacoma, and says it has a hot, astringent taste. Prosper Albinus 

 thinks that the root noticed by Dioscorides was that of the R. rkaponticum, 

 which was obtained by him in Thrace, and cultivated in Persia. It was, 

 however, known to Paulus ^Eginetus and others, and appears to have been 

 familiar to the early Arabian writers, one of whom, Mesue, speaks of three 

 kinds, differing in quality. 



Notwithstanding this early use of Rhubarb, there is as much ignorance 

 respecting the plant or plants producing it, as when it first came into notice ; 

 all that science has accomplished is rather to have ascertained by what spe- 

 cies it is not afforded, than to point out those that do. The species inhabit 

 the great plains of Tartary, the steppes of Siberia, and the great ranges of 

 mountains lying between these and the northern parts of India. Those now 

 known, resemble each other very much in their flowers, and their principal 

 specific differences are to be found in the leaves, and more especially in the 

 footstalks. Those that have been cultivated have become so changed that it 

 is difficult to recognise from what wild species they are derived. 



Dr. Royle says, " The Rhubarb of commerce is well known to be brought 

 by the Chinese to the Russian frontier town of Kiatcha, according to the 

 treaty formed between those powers in 1772. The Chinese obtain the Rhu- 

 barb produced in China proper, from that part of the province of Shensee, 

 called Kansu, situated between the -35° and 40° N. Lat. ; but the best, ac- 

 cording to the missionaries, who say it is called Tai-hoang, in the province 

 of Luet-chen, from the mountains called Sue-chan, or of snow, which extend 

 from 26° to 33° N. Lat., and from about 100° to 105° E. Long. That from 

 the latter province probably forms much of what is called Chinese Rhubarb; 

 the missionaries met large quantities of it, brought down in the months of 

 October and November. That from Kansu may afford some of what is called 

 Russian Rhubarb ; but both Pallas and Rehman have ascertained that the 

 greater portion, if not the whole of this, is obtained in April and May, from 

 the clefts of rocks in high and arid mountains surrounding Lake Kokonor. 

 Bell also learnt that it was the product of Mongolia, and Marco Polo of Suc- 

 cuir iq Tanguth. Dr. Rehman ascertained that the trade is in the hands of 

 one Bucharian family, who farm the monopoly from the Chinese govern- 

 ment, and reside at Si-ning, a Chinese town on the very frontiers of Thibet, 

 3000 versts from Kiatcha, and 20 days' journey from Kian-Sin and Sehan- 

 sin, Tangutian towns, where the Bucharians go to purchase Rhubarb. This 

 would bring the Rhubarb country within 95° E. Long., and 35° N. Lat., 

 that is, the heart of Thibet." {Illus, Him. Bot.) He goes on to say, that 

 as no naturalist has visited this part, and neither plants nor seeds have been 

 obtained thence, it is as yet unknown what species yields the Rhubarb. In 

 this opinion he is supported by Sievers, sent by the Russian government to 

 investigate the subject ; and still more recently, Calau the apothecary at the 

 Russian factory at Kiatcha states all that is known of the Rhubarb plant is 

 erroneous, and that neither the true plant nor its seed have ever been obtained. 



The following species of Rhubarb are all that are known as possessing any 

 properties entitling them to notice, according to Dr. Lindley, from whose 

 account of them, with those of Royle, Pereira, and Guibourt, the present 

 synopsis of them is drawn up. 



* Having spike-like racemes. 



1. R. spiciforme, Royle. — Leaves thick, leathery, cordate, blunt, red, and reticulated be- 

 neath, and covered with stellate down on each side. Petioles and peduncles smooth. 

 Racemes arising from the root, spicate. 



Royle, Illus. 318, t. 78 ; Lindley, Flor. Med. 355. 



