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PHARMACOGNOSY. 
Constituents. — A glucoside glycyrrhizin from 2 - 5 
to 6 per cent. (Russian licorice is said to contain as 
much as 7'5 per cent.), asparagin 3 per cent., glycyra- 
marin, mannit, starch, calcium oxalate and resin. 
Allied and Other Plants. — The root of wild lico- 
rice, Glycyrrhiza lepidota,u perennial herb indigenous to 
Western North America, is somewhat similar to Span- 
ish licorice, but is more bitter and less sweet. Glycyr- 
rhizin has also been obtained from the roots of Abrus 
precatorius and Ononis spinosa, the rhizome of Polypo- 
dium vulgare and various parts of a number of other 
plants. 
RHEUM (Rhubarb). 
The rhizome of Rheum officinale, Rheum palmatum , 
Rheum palmatum, var. tanguticum, and probably other 
species of Rheum (Fam. Polygonacete), perennial herbs 
indigenous to Northwestern China and Eastern Thibet, 
and sparingly cultivated in other parts of the world. 
The rhizomes are collected in autumn from plants that 
are eight to ten years old, most of the bark is removed, 
and they are then perforated, strung on ropes and 
dried either in the sun or by artificial heat. The drug 
is exported chiefly from Shanghai. The principal 
commercial varieties are known as Chinese rhubarb, 
Canton rhubarb and Shensi rhubarb, the latter being 
preferred. 
Description. — Cut into irregular plano-convex and 
oblong pieces, frequently with a large perforation, hard 
and moderately heavy, 5 to 15 cm. long, 5 to 8 cm. 
broad and 3 to 6 cm. thick ; externally mottled from 
alternating striae of light-brown parenchyma cells and 
dark -brown medullary rays, occasionally with reddish- 
brown cork patches and small radiate scars of fibro- 
vascular tissue, smooth and sometimes covered with a 
