400 BOTANY AND PHARMACOGNOSY. 



The rhizome of the large Button-snakeroot (Lacinaria scari- 

 osa), growing in the eastern and central portion of the United 

 States and Canada, contains o.i per cent, of volatile oil, about 5 

 per cent, of resin, and 2 per cent, of a caoutchouc-like substance. 



Coltsfoot {Tussilago Farfara) is a plant indigenous to 

 Europe and naturalized in the Northern United States and Can- 

 ada. It is an acaulescent herb with a slender rhizome 30 to 40 

 cm. long ; nearly orbicular, somewhat lobed and tomentose leaves, 

 and large, solitary, yellow flowers appearing before the leaves. 

 The plant contains an acrid volatile oil, a bitter glucoside, resin 

 and tannin. 



Echinacea is the root of Brauneria (Rudbeckia) purpurea, 

 a plant growing in rich soil from Virginia to Illinois and south- 

 ward, and of B. pallida, growing from the Northwest Territory 

 to Texas. It occurs in pieces from 5 to 10 cm. long and 5 to 15 

 mm. in diameter; it is grayish-brown or reddish-brown exter- 

 nally, longitudinally wrinkled, sometimes spirally twisted; the 

 fracture is short, the fractured surface exhibiting a number of 

 resin cells and a greenish-yellow wood. The odor is distinct 

 and the taste is aromatic, acrid and pungent. The drug contains 

 an alkaloid and 0.5 to i per cent, of an acrid resinous substance 

 to which the medical properties are due. 



Rosin Weed or Compass Plant {Silphium laciniatum), 

 found growing from Ohio to South Dakota and south to Texas, 

 produces an oleo-resin which exudes either spontaneously or from 

 the punctures of insects, and contains about 19 per cent, of vola- 

 tile oil, and 37 per cent, of acid resin. 



The Thistle (Cnicus benedictns) contains a crystalline bitter 

 principle, cnicin, which is colored red with sulphuric acid. 



The Mexican drug pipitzahoac is the rhizome of Peresia 

 Wrightii, P nana and P adnata, plants found in Southwestern 

 Texas and Mexico. It contains about 3.6 per cent, of a golden- 

 yellow crystalline principle, pipitzahoic acid, which appears to be 

 related to oxythymoquinone and is colored an intense purple with 

 alkalies and alkaline earths. 



Lion's foot, the root of Nahalus Serpentaria, N. alba and 

 other species of Nabalus growing in the United States, contains 

 bitter principles, resin and tannin. Mio Mio {Baccharis cordi- 



