CLASSIFICATION OF ANGIOSPERMS. 723 



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) pur pur ea, 

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

 ward, and of B. angustifolia, growing from the Northwest Terri- 

 tory to Texas (Fig. 399). 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 benedictus) contains a crystalline bitter 

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



The Mexican drug PIPITZAHOAC is the rhizome of Perezia 

 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 Prenanthes Serpentaria, P. alba and 

 other species of Nabalus growing in the United States, contains 

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

 folia), of South America, is poisonous to sheep and cattle and 

 contains an alkaloid, baccharine, and a bitter principle. SPINY 

 CLOTBUR (Xanthium spinosum) contains a bitter resin and possi- 

 bly a volatile alkaloid. The fruit of Xanthium spinosum, a 

 common weed naturalized from Europe, contains an amorphous, 

 non-glucosidal substance, xanthostrumarin, which forms precip- 

 itates with a number of the alkaloidal reagents. SNEEZE- WEED 

 (Helenium autumnale) contains a volatile oil, a bitter glucoside 

 and tannin. Helenium tenuifolium, of the Southern United States, 



