CLASSIFICATION OF ANGIOSPERMS. 



271 



in racemes. The flowers are zygomorphic and somewhat resem- 

 ble those of Aconite. 



Pulsatilla, which was formerly official, is obtained from 

 several species of Anemone growing in Europe. These are peren- 

 nial herbs (Fig. 76) with basal leaves which arc deeply lobed 

 or dissected, those of the stem forming a kind of involucre near 

 the flower. The flowers are rather large and with numerous 

 petaloid sepals. The fruit is a densely woolly akene in those 



Fig. 142. Aconitine: orthorhombic crystals, crystallized from alcoholic solutions. 



species which are used in medicine. The entire plant is used and 

 contains an acrid volatile oil the principal constituent of v/hich is 

 an anemone camphor (anemonol). The latter is easily decom- 

 posed into anemonin, which on fusion becomes exceedingly acrid. 

 Similar principles are found in other species of Anemone as well 

 as in certain species of Ranunculus (buttercup) and Clematis 

 vitalha of Europe. 



Very many of the other Ranunculaceae contain active princi- 

 ples. The glucoside helleborein, which resembles digitalin in its 

 medicinal properties, is found in Hellehorus niger the black hel- 



