[Footnote 184: Mr. Pallas (to whom I am chiefly indebted for this account of the Tartarian and Siberian Rhubarb) assured me, that he never found the R. Palmatum in any part of Siberia.]
[Footnote 185: Phil. Trans. for 1765, p. 290.]
[Sidenote: R. Rhaponticum.] The leaves of the R. Rhaponticum are round, and sometimes broader than they are long. This species is found abundantly in the loamy and dry deserts between the Volga and the Yaik[186], towards the Caspian Sea. It was probably from this sort that the name Rha, which is the Tartarian appellation of the river Volga, was first applied by the Arabian physicians to the several species of rheum. The roots however which grow in these warm plains are rather too astringent; and therefore ought not to be used in cases where opening medicines are required. The Calmucs call it Badshona, or a stomachic. The young shoots of this plant, which appear in March or April, are deemed a good antiscorbutic; and are used as such by the Russians. The R. Rhaponticum is not to be found to the West of the Volga. The seeds of this species produced at Petersburg plants of a much greater size than the wild ones: the leaves were large, and of a roundish cordated figure.
[Footnote 186: The Yaik falls into the Caspian Sea, about four degrees to the East of the Volga.]
[Sidenote: R. Rhabarbarum.] The R. Rhabarbarum grows in the crevices of bare rocky mountains, and also upon gravelly soils: it is more particularly found in the high vallies of the romantic country situated beyond Lake Baikal. Its buds do not shoot before the end of April; and it continues in flower during the whole month of May. The stalks of the leaves are eaten raw by the Tartars: they produce upon most persons, who are unaccustomed to them, a kind of sphasmodic contraction of the throat, which goes off in a few hours; it returns however at every meal, until they become habituated to this kind of diet. The Russians make use of the leaves in their hodge-podge: accordingly, soups of this sort affect strangers in the manner above mentioned. In Siberia the stalk is sometimes preserved as a sweet-meat; and a custom prevails among the Germans of introducing at their tables the buds of this plant, as well as of the Rheum Palmatum, instead of cauli-flower.