RHEUM. 



fmooth -, veins fomewhat hairy beneath ; the finus dilated 

 at the bafe : ilalks furrowed on the upper fide, rounded at 

 the edge." — Native of Afia, and cultivated, like all the 

 other fpecies (except Leucorrhi-z.um), at Kew, where they 

 moftly flower in May and June. — Root large and thick, much 

 divided, reddifh-brown on the outfide, yellow within. Stems 

 from two to three feet high, jointed, purple. Leaves not 

 expanded at firft, but folded, fmooth, roundifh heart-lhaped, 

 on thick, reddifh, channelled ilalks, which have an acid fla- 

 vour, and are ufed for making tarts. Flowers white, form- 

 ing a thick, obtufe, denfe tuft, which becomes a panicle of 

 large, triangular, hrovin feeds. 



2. R. undulatum. Waved-leaved or Chinefe Rhubarb. 

 Linn. Sp. PL 531. Amoen. Acad. v. 3. 230. t. 4. — 

 " Leaves rather hairy, undulated ; the finus dilated at the 

 bafe : italks flat above, fharp at the edges." — Native of 

 China and Siberia. — Root compofed of numerous thick fibres, 

 running further into the ground, and of a deeper yellow than 

 the foregoing. Stem upright, three or four feet in height, 

 of a pale brownifh colour. Leaves fomewhat tapering, 

 much waved at their edges, ilrongly veined beneath. 

 Flowers, white, in loofe panicles or bunches. Seeds of a 

 rufty brown. 



3. R. palmatum. Officinal or Turkey Rhubarb. Linn. 

 Sp. PL 531. Mill. Illuftr. t, 30. Woodv. Med. Bot. 

 127. t. 46. — " Leaves palmate, pointed, roughifh ; the finus 

 dilated at the bafe : ftalks obloletely furrowed above, round- 

 ed at the edge." — Native of China and Tartary. — Root pe- 

 rennial, thick, oval, fending forth numerous tapering 

 branches, externally brown, internally yellow. Stem eredt, 

 fix or eight feet high, round, hollow, jointed, fheathed, 

 flightly furrowed, branched towards the top. Radical-leaves 

 numerous, large, rough, roundifh, deeply lobed ; Jlem-leaves 

 one at each joint, from a membranous fheath, fmaller up- 

 wards. Flowers of a greenifh- white colour, furrounding the 

 branches in numerous cluilers, forming a kind of fpike. 



The roots of this and the lalt fpecies conftitute the drugs 

 which in our (hops are known by the names of Chinefe and 

 Turkey Rhubarb, although other fpecies of Rheum, efpe- 

 cially eompaclum, pollefs like medicinal properties, and their 

 roots are of courfe fpmetimes fubftituted for the true ones. 

 Profed'or Martyn and Dr. Woodville have taken great pains 

 to illultrate this genus, fo juftly celebrated for its purgative 

 qualities. Dr. Pulteney remarks, that if R. undulatum and 

 R. palmatum are planted near each other, they produce a 

 hybrid variety, more excellent in kind than the parent 

 plants. 



4. R. compaftum. Thick-leaved Rhubarb. Linn. Sp. 

 PL 531. Mill. Ic. v. 2. 145. t. 218. -Leaves fomewhat 

 lobed, very obtufe, lucid, fharply toothed, quite fmooth. 

 — Native of Tartary. -Roots large, much divided, yellow 

 within. Stems five or fix feet high, green, branched at the 

 upper part. Leaves long, broad at the bafe, coriaceous 

 and compaft, rather waved, and having a (harp acid flavour. 

 Flowers white, forming an ereft panicle or fpike. This is 

 frequently fubllituted for the real rhubarb. 



5. R. tartaricum. Tartarian Rhubarb. Linn. Suppl. 

 229. Willd. n. 5. — Leaves ovate, heart-fhaped, undivided, 

 flat, fmooth, on roundifh, angulated (talks. Panicle fur- 

 rowed Native of Lefl'er Tartary. We know of neither 



fpecimen nor figure of this fpecies. Linnaeus defcribed it 

 from the Upfal garden as having large leaves, the radical 

 ones procumbent, with dilated veins, on red Ilalks, which 

 are convex beneath, bifiorefence fcarcely higher than the 

 leaves. 



6. R. Ribes. Warted-leaved Rhubarb. Linn. Sp. PL 

 532. Desfont. in Ann. du Muf. v. 2. 261. t. 49. (La- 



pathum orientale, afpero et verrucofo folio, Ribes Arabi- 

 busdiftum; Dill. Elth. v. I. 191. t. 158. f. 192.) —Leaves 

 very obtufe, verrucofe, with fpinous veins beneath ; italks 

 flat above, rounded at the margin. —Native of the Levant ; 

 on mount Libanus, and other mountainous parts of Syria! 

 —Root thick and fiefhy. Stems two feet high, hairy, green, 

 tinged with purple towards the bottom. Leaves large', 

 curled at the edges, veined, of a purphfli-green colour,' 

 paler beneath, ftudded with warts. Linnaeus, who had' 

 never feen the flower, referred this plant to Rheum from its 

 habit. 



7. R. hybridum. Baflard Rhubarb. Willd. n. 7. Murray 

 in Comment. Gott. 1779, 7- l - '• Leaves fmooth above, 

 rather hairy beneath, (lightly lobed, acute ; the finus nar- 

 rowed at the bafe ; italks obfeurely furrowed above, rounded 



at the margin — Native of the north of Afia Very fimi- 



lar in habit and appearance to R. palmatum, and we are much 

 difpofed to confider it, with profellor Murray, as a hybrid 

 plant produced between that and fome other fpecies. The 

 leaves of this are not fo much nor fo deeply cut as thofe of 

 palmatum. 



8. R. leucorrhizum. White-rooted Rhubarb. Willd. 



n. 8. Pallas Nov. Aft. Petrop. 1792, 381 Leaves 



tranfverfely oval, deprefled. Panicle divaricated when in 

 feed. Two fegments of the calyx many times larger than 

 the reft. — Native of defart places, on the mountains of Si- 

 beria Adopted by Willdenow, on the authority of Pallas, 



who defcribes it thus. " Radical-leaves uiually three, pro- 

 cumbent, four or five inches wide, three-nerved, much 

 veined, fmooth, coriaceous, lengthened out at the bafe • 

 rough at the edges, with very minute, cartilaginous, acute 

 crowded teeth. Stalks comprefi'ed, fmooth, folid, fucculent. 

 Flowering-Jlem a fpan high, furrowed, panicled." 



Rheum, in Gardening, contains plants of the herbaceous, 

 perennial, luxuriant kind, of which the fpecies chiefly culti- 

 vated are ; the rhapontic or common rhubarb ( R. rhapon- 

 ticum) ; the palmated-leaved iR. palmatum); the com- 

 pact thick-leaved rhubarb (R. eompaclum) ; the waved- 

 leaved Chinefe rhubarb (R. undulatum) ; the warted-leaved 

 Perfian rhubarb R. ribes) ; and the Tartarian or heart- 

 leaved rhubarb {R. tartaricum. ) 



It is dated, on the authority of feveral cultivators of the 

 firit fpecies of this plant, by the editor of Miller's Dic- 

 tionary, that by proper attention in the growth and prepa- 

 ration of the root, it may be obtained here nearly in equal 

 goodnefs to the foreign. 



Method of Culture. — Thefe plants are all increafed by 

 feeds, which fhould be fown in autumn foon after they are 

 ripe, where the plants are defigned to remain, as their roote 

 being large and flefhy when they are removed, they do not 

 recover it foon ; nor do the roots of fuch removed plants 

 ever grow fo large and fair as thofe which remain where they 

 were fown. When the plants appear in the fpring the 

 ground fhould be well hoed over, to cut up the weeds ; and 

 where they are too clofe, fome ihould be cut up, leaving 

 them at the firft hoeing fix or eight inches afunder ; but at 

 the fecond, they may be feparated to a foot and a half 

 diftance, and more. When any weeds appear, the ground 

 fhould be fcuffled over with a Dutch hoe in dry weather ; 

 but after the plants cover the ground with their broad 

 leaves, they keep down the weeds without any further trou- 

 ble. The ground fhould be cleaned in autumn when the 

 leaves decay, and in the fpring, before the plants begin to 

 put up their new leaves, be dug well between them. In the 

 fecond year, many of the ftrongeft plants will produce 

 flowers and feeds, and in the third year moil of them. It is 

 advifed, that the feeds be carefully gathered when ripe, and 



not 



