SiLENALES.] POLYGONACE^. 503 



There are few parts of the world which do not acknowledge the presence of plants of 

 this Order. In Europe, Africa, North America, and Asia they occupy ditches, hedges, 

 and waste gi'ounds, in the fonn of Docks and Persicarias ; the fields, mountains, and 

 heaths as Sorrels and traihng or twining Polygonums ; in South America and the 

 West In(.hes they take the form of Coccolobas or Seaside-grapes ; in the Levant of 

 Rhubarbs ; and even in the desolate regions of the North Pole tliey ai'e found in the 

 shape of Oxyria. 



Son-el on the one hand, and Rhubarb on the other, may be taken as the representa- 

 tives o: the general quaUties of this Order. Wliile the leaves and yoimg shoots arc acid 

 and agreeable, the roots are universally nauseous and pm'gative. To these two qualities 

 is to be superadded a thu'd, that of astiingency, wliich is found in a greater or less 

 degi'ee in the whole Order, but wliich becomes in Coccoloba uvifera so powerful as to 

 rival gmn Kuio m its effects. Some of the Polygonums are also acrid, as the P. Hydro- 

 piper, which is said to blister the skin, and there is a species of Polygonum, called 

 Cataya in the language of the Brazilian Indians, which has a very bitter peppery taste, an 

 infusion of the ashes of which is used to puinfy and condense the juice of the sugar-cane, 

 and is employed on the Rio St. Fx-ancisco with advantage in the disease called O Largo, 

 an enlargement of the colon, caused by debihty. Oxalic acid is copiously formed in 

 both Docks and Rhubarbs; the latter moreover contains nitric and mahc acids m al)un- 

 dauce, and it is these which give an agreeable taste to the stalks of the latter when 

 cooked, but which also render them so ill-suited to the digestion of some persons. For 

 the facts concerning the qualities and origin of the Rhubarbs in medical use, the reader 

 may consult Royle, Guibourt, Pereira, Geiger, Endhcher, and the Flora Medka. 

 It seems probable that some at least of the Turkey Rhubarb is Rheum palmatum, that 

 R. midulatum is also largely collected, and that R. Emodi and Webbianum furnish the 

 Rhubarb used in the hospitals of India. Goebel positively contradicts the statement 

 made by some writers that Rheum leucorhizum yields a fine sort of Rhubarb ; he says 

 that it has an insipid slimy taste, not at all hke that of Rhubarb. — A7in. Ch. 1. 118. 

 Before this sort of drug was so common, the roots of Rumex alpinus were employed in 

 its stead, under the name of Monk's Rhubarb ; it is however much less active. The 

 Rheum Ribes, called Riwasch or Ribas in the East, furnishes the Arabs with an acidulous 

 medicine, and its leaf-stalks are used in the preparation of sherbet. Docks are species of 

 Rumex ; their prevailing character is astringency, which has given them some celebrity 

 as remedies for diarrhoea, and as stomachics. R. Patientia {XairaQov K-qirivrov), although 

 now expelled from gardens, was once esteemed as a subacrid potherb, and its roots were 

 used as laxatives. Sorrels, whose acidity is chiefly owing to oxaUc acid, are all species 

 of this same genus ; the most esteemed among them for garden purposes is R. scutatus. 

 A legion of species fonns the genus Polygonum, celebrated in various ways. Some are 

 used in dyeing, especially P. tinctorium, which yields a blue hardly inferior to indigo, 

 and is largely cultivated for it in France and Flanders. Of P. Hydropiper the leaves 

 are so acrid as to act as vesicants ; it is reputed to be a powerful diuretic, but to lose 

 its activity by drying, on wliich account it requires to be used fresh ; it will dye wool 

 yellow. P. Bistorta is a useful astringent ; the decoction may be employed in gleet 

 and leucorrhoea, as an injection, as a gargle in relaxed sore throat and spongy gums, 

 and as a lotion to ulcers attended with excessive discharge ; internally it has been 

 employed, combined with Gentian, in intermittents ; it may also be used in passive 

 haemorrhages and diaiThoea. Several of the Brazihan Polygonums ai*e said by Martins 

 to be useful as astringents, and to be employed in the treatment of syphilis. The nuts 

 of Fagopjrrum esculentum, or Buckwheat, tataricum, and others, are used as food for the 

 sake of their mealy albumen ; those of P. aviculare are said to be powerfully emetic 

 and purgative ; but this is doubted by Meisner. The seeds of Polygonum barbatum 

 are used as medicuie by Hindoo practitioners, to ease the pain of griping in the colic. 

 The leaves of P. liispidum are said by Humboldt to be substituted in South America 

 for Tobacco. Coccoloba americana, remarkable for the succulent \dolet calyx in which 

 its nuts are enveloped, is on that accovmt called the Seaside-grape in the West Indies, 

 and yields an extremely astringent extract ; its wood dyes red ; its cmi-ant-hke berries 

 are acid, pleasant, and eatable. The root of Calhgonum Pallasia, a leafless shinib foimd 

 m the sandy steppes of Siberia, furnishes from its roots, when pounded and boiled, a 

 gummy nutritious substance, resembling Tragacanth, on which the Calmucks feed in 

 times of scarcity, while they chew the acid branches and finiits to allay then* thirst. 

 Muhlenbeckia adpressa is stated by Mr. Backhouse to have clusters of currant-like 

 fruits of a sweetish taste, which have been made mto pies and puddings in the penal 

 settlements of Australia. The tiimk and branches of Triplaris americana are cliam- 

 bered hke those of the Cecropia, or Trunipet-trcc, and serve for the habitation of light- 

 brownish ants, which inflict a most painful hitcSchomburf/k; in Ann. N. II. 1. 20(j. 



