POLYGONACEJE. 



Leaves thick, leathery, cordate, blunt, red and netted beneath, and 

 covered with stellate down on each side ; petioles and peduncles smooth. 

 Racemes arising from the very root, spicate. Pedicels numerous, clus- 

 tered, as long as the ripe fruit. Sepals oblong, obtuse, the alternate 

 ones narrower and petaloid. Fruit rounded at the base and apex. 

 Nothing is said of the quality of the roots, except that they are lighter 

 coloured and more compact than those of R. Emodi. It appears that 

 the rhubarb of Tartary grows at the height of 16,000 feet above the sea ; 

 and Dr. Royle says that rhubarb sent by the late Mr. Moorcroft from 

 near Ludak, lat. 34 N., long. 7?i E,, was, for compactness of texture, 

 colour and properties, as fine as any he has ever seen ; it is not impro- 

 bable that it may have been furnished by this species. 



735. R. Moorcroftianum Roykillustr. p. 318 Wall. herb. 



ind. n. 1727. (" Small stalked rhubarb/') 



This plant has not been described. Professor Don has obliged me 

 with the following notes upon the differences between it and R. spici- 

 forme : " R. Moorcroftianum has the petioles more deeply furrowed ; 

 the stipules as long as the petioles, and much more membranous. The 

 imperfect rudiments of leaves (scales) at the base are even longer than 

 the stipules, and are extremely thin and much torn, especially towards 

 their summits. The fruits are larger, and angles broader and more winged. 

 R. spiciforme has the lamina of its leaf of a thicker and firmer texture ; 

 the stipules twice or thrice shorter than the petioles. The imperfect 

 rudiments of leaves (scales) on the collum are short, entire, and less 

 membranous, and imbricated. These scales in the former (Moorcrofti- 

 anum) are often longer than the petioles. The leaves and stems of both 

 species are clothed with short scabrous pubescence, and the sepals 

 agree in size and form. Root of this is said to be more purgative than 

 the last. 



736. R. leucorhizum Pall. n. act. petrop. x. 381. 1 792. Willd. 

 sp. pi. ii. 491. Ledebour ic. pi. ross. t. 491. fl. altaic. ii. 92. 

 R. nanum Sievers in Pall. n. nord. beitr. vii. 264. R. tataricum 

 Linn. Suppl. 229. ? Stony places on the mountains of Dolen- 

 kara, Tschingistau and Arkalyki in the Soongorian Kirghese 

 desert ; also near the rivers Dschargurban and Kurtschum. 



A small plant for this genus. Root white, branched, about 3 inches 

 in diameter next to the stem. Radical leaves about 3, short-stalked, 

 coriaceous, 4-6 inches long, 5-9 inches broad, transversely elliptical, 

 scarcely hollowed out at the base ; with 3, thick, branched nerves pro- 

 jecting very much beneath ; smooth on both sides, toothletted at the 

 edge, with here and there a few scattered roughish warts ; no cauline 

 leaves, or scarcely ever one ; petioles about an inch long, comp. essed, 

 solid, with a narrow channel on the upper side. Flowering stem about 

 2 inches high, when in flower, afterwards becoming 10-12 inches high, 

 about as thick as the finger, simple as high as the middle, then divided 

 into several rigid divaricating branches. Flowers much fewer than in 

 other species ; the alternate segments of the calyx 3 or 4 times smaller 

 than the others. Fruit very large, 6 lines broad and 4 lines long, or even 

 longer, deep red. Ledebour. Ledebour says nothing of the roots. 

 " When Pallas was at Kiachta, the Buchanan merchants who supplied 

 the crown with rhubarb, brought some pieces of rhubarb, which had a 



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