486 BOTANY AND PHARMACOGNOSY. 



. gentiamarin, which is amorphous, has a disagreeable bitter taste 

 and gives a sHght darkening with iron salts ; and gentianin, which 

 occurs in yellowish needles, gives a greenish-black color with 

 ferric salts and on hydrolysis yields gentienin, xylose and glucose. 

 Allied Plants. — The rhizomes and roots of various other 

 European species of Gentiana are sometimes collected and em- 

 ployed medicinally, as of Gentiana purpttrea, collected in Switzer- 

 land, and G. Pannonica and G. Punctata, collected in Austria. 

 The rhizome and roots of Elliott's gentian, Gentiana Elliottii, 

 indigenous to the southeastern part of the United States, was at 

 one time official in this country. 



Fig. 211. Rhizome of African ginger showing scars of overground branch (Ls) and 

 buds (k). The' more or less parallel lines represent leaf-scars and scars of bud-scales, and 

 the small circles, root-scars. — After Meyer. 



The root of American Columbo, also known as yellow gentian 

 (Frasera carolinensis) , a perennial herb growing in the Eastern 

 United States and Canada, resembles in the whole condition the 

 official gentian, but is of a lighter color (p. 460). 



ZINGIBER.— GINGER.— The rhizome of Zingiber officinale 

 (Earn. Zingiberaceje), a perennial herb (Fig. 132) indigenous to 

 Asia, and cultivated in most tropical countries, notably in the West 

 Indies and Africa (p. 242). The rhizomes are collected between 

 December and March ; they are cleaned by washing, peeled, again 

 washed in water, sometimes containing juice of the lime fruit, 

 and dried in the sun. There are several kinds of the drug, depend- 

 ing upon the manner of treatment. That from Africa has the 



