POLYGONACEJE. 



very wavy, deep green, of a thick texture, glossy and rather even on the 

 upper side, scabrous at the edge, slightly downy on the under side, but 

 quite smooth above j sinus a little open ; the lobes of the leaves quite 

 rolling inwards. Petiole pale green, with scarcely a tinge of red, 

 minutely downy, semicylindrical, with elevated edges to the flat upper 

 side, which is of equal breadth at each end. The plant described by 

 Dr. Ledebour in his Flora Altaica is certainly not R. rhaponticum, as is 

 proved by the form of its petiole ; nor can I see how it differs from 

 R.^caspicum of which there exists a plant from Dr. Fischer himself, in 

 the Apothecaries' Garden, Chelsea. 



740. R. compactum Linn. sp. pi 531. Mitt. diet. t. 218. 

 Willd. sp. pi. u. 489. Tartary, China. Linn. 



Leaves heart-shaped, obtuse, very wavy, deep green, of a thick tex- 

 ture, scabrous at the margin, quite smooth on both sides, glossy and 

 even on the upper side; sinus nearly closed by the parenchyma. 

 Petiole green, hardly tinged with red except at the base, semicylindrical, 

 a little compressed at the sides, with the upper side broad, flat, bordered 

 by elevated edges, and of equal breadth at each end. Guibourt says 

 that the root of this is a pretty good imitation of Chinese Rhubarb ; 

 but when cleared of the yellow powder that covers it, there is no 

 difficulty in recognising it by its reddish or whitish red colour, its smell 

 of " rhapontic " (in which respect it corresponds with undulatum), its 

 close radiated marbling, its staining the saliva yellow only in a slight 

 degree, and in its not being gritty. 



741. R. palmatum Linn, sp.pl. 531. Ait. Kew. ii. 41. Willd. 

 sp. pi. ii. 489. Woodv. t. 46. S. and C. t. 25. Country 

 about the great wall of China, Linn. ; a long chain of mountains, 

 partly naked of forests, which, skirting Chinese Tartary on the 

 west, commence to the North not far from the town of Selia, 

 and extend to the South as far as Lake Kokonor, near Thibet, 

 Murray. 



Leaves roundish-cordate, half palmate ; the lobes pinnatifid, acumi- 

 nate, deep dull green, not wavy, but uneven and very much wrinkled 

 on the upper side, hardly scabrous at the edge, minutely downy on the 

 under side ; sinus completely closed : the lobes of the leaf standing 

 forwards beyond it. Petiole pale green, marked with short purple 

 lines, terete, obscurely channelled quite at the upper end. Flowering 

 stems taller than those of any other species. I have already men- 

 tioned under R. undulatum how this has obtained the character of being 

 at least one of the sources of Tartarian Rhubarb. Pallas was however 

 assured by the Bucharian Rhubarb merchants that they knew nothing 

 of such leaves as those of this species, and that the leaves of genuine 

 Rhubarb were round and much cut at the edges. Pallas considered 

 this account to agree best with R. compactum, whose leaves however 

 are more wavy than cut. Nevertheless the opinion that R. palmatum 

 is the source of the true officinal rhubarb continues to be generally 

 entertained. In the last edition of the London Pharmacopoeia this is 

 asserted ; and M. Guibourt declares that of all the cultivated kinds 

 R. palmatum alone resembles exactly, in its odour and smell, the 

 rhubarb of China. It is stated by Stevenson and Churchill that R . pal- 

 matum is extensively cultivated near Banbury for the supply of the 

 London Market. 



358 



