122 THE NEW RHUBARB CULTURE. 



The medicinal species is grown in the same way as 

 the varieties cultivated for stalks. In field culture, a 

 light plow furrow should be made on each side of the 

 rows, thus covering the crown buds of the plants with 

 a layer of soil, which will form a ridge to throw off the 

 water and afford winter protection. In spring, this 

 ridge will be smoothed down with a light harrow. The 

 roots will be large enough for removal at the end of 

 four years' growth, although it is claimed that a further 

 growth of one or two years increases their medicinal 

 value. The drug is often prescribed as a cathartic. The 

 following account of the medicinal variety and its cul- 

 tivation is by Mr. William Saunders, late superintendent 

 of gardens and grounds at the U. S. department of 

 agriculture : — 



It is now generally admitted that the true source of 

 the best rhubarb of commerce is Rheum officinale. This 

 species is a native of Thibet. It is a plant of robust 

 growth, often reaching five to six feet in height, and 

 produces large heavy masses of flowers. The leaves are 

 sometimes five feet long. The ordinary species of rhu- 

 barb are herbaceous perennials, with a thick rootstock 

 and deciduous leaves. In Eheum officinale, after the 

 third or fourth year from seed, the rootstock gradually 

 decays and a stem is formed above the ground ; the plant 

 then derives its nourishment from small roots, which 

 cannot be employed in medicine. These stems have thick 

 branches, often six to eight inches in diameter. The 

 portion used in medicine is therefore the stem, and not 

 the rhizome or root. 



Seeing that the sources of rhubarb are so numerous, 

 it may well be expected that its commercial distinctions 

 and medicinal values are equally varied. The quality of 

 the article will be influenced by its botanical origin, 

 the climate and soil in which it was grown, the age of 

 the root, the season when gathered, the method of collec- 

 tion, the process of drying, and its final preparation for 



