RICE OF ECONOMIC PLANTS. 351 



etc., perennial plants of the Buckwheat family (Polygonacere), 

 natives of Eussia, the range of the Himalaya, and Western 

 Cliina. From the latter country large quantities of the roots 

 enter Eussia, from which place the best Ehubarb comes to tliis 

 country. The roots of E. Emodi find their way to Aleppo 

 thence to Constantinople, and from there to this country under 

 the name of Turkey Ehubarb. There has been, until recently, 

 much doubt as to the species which produces the best medi- 

 cinal rhubarb. It seems, however, to be clear tliat it is to be 

 attributed to B. officinale and R. ixdmatum, the Chinese and 

 Tartars not being willing that the plant should be known. But 

 the quality in a great measure depends on the collecting, drying, 

 and transport. B. 'palmahhm is not now grown in this country 

 for medicinal purposes, but i?. PJicqoonticum is to a large ex- 

 tent, principally near Banbury ; it is also extensively cultivated 

 for its leaf-stalk, which is well known as a culinary vegetable, 

 B. undulatum and B. palmatitm being used for the same purposes, 

 as well as being made into wine and preserves. 



Ehubarb contains numerous crystalline bodies, in botany 

 called raphides, which, by the aid of the microscoj)e, are readily 

 seen in the fresh or cooked leaf-stalk, having the appearance of 

 numerous needles, and said to consist of phosphate of lime, and 

 it is supposed that the medical virtue of rhubarb is in some way 

 due to them, it being one of our best purgative medicines. 



Rhubarb, Monk's, a name applied to Bumex aljjimis, a 

 strong-rooted perennial of the Buckwheat family (Polygonaceae), 

 native of Switzerland. It has the appearance of Ehubarb, but 

 its leaves are smaller and heart-shaped. It has become natu- 

 ralised in the mid-counties of Scotland, wdiere it is known by 

 the above name. It has been used medicinally as Ehubarb, 

 but is of a drastic nature. 



Rice {Oryza sativa), an annual corn-grass similar in habit of 

 growth to barley, but almost an aquatic, requiring to be flooded 

 in the early part of its growth. It is extensively cultivated in 

 India and other Eastern countries. It was early introduced into 

 America, especially the Southern States of Carolina and Georgia, 



