MEDICINAL PLANTS 



NORTH AMERICA. 



PH^ENOGAMOUS OR FLOWERING PLANTS. 



CLASS I. — DICOTYLEDONOUS OR EXOGENOUS PLANTS. 



Stems with bark, wood, and pith distinct ; when perennial, increasing 

 in size by the annual addition of a layer of wood outside that already 

 formed. Leaves net-veined. Parts of the flower commonly in fives or 

 fours. Embryo with two cotyledons, or seed-leaves, rarely with several in 

 a whorl. 



Division I. — Polypetalous Exogenous Plants. 



Flowers with both calyx and corolla, the latter absent in only a few 

 genera and species. Petals each separate and distinct. 



RANUNCULACE/E. 



Character of the Order. — Calyx : sepals 3 to 6, generally 5, distinct, 

 usually deciduous, and, except in clematis, imbricated in the bud. Corolla : 

 petals 3 to 15, occasionally irregular or deformed, and sometimes absent. 

 In the latter case the sepals are usually colored, and petal-like. Stamens 

 indefinite, distinct, very rarely few and definite. Ovaries numerous, rarely 

 few or solitary, distinct. Ovules solitary or several, inverted. Fruit either 

 achenia, seed-like, dry follicles, or berries ; seeds solitary or several. Em- 

 bryo minute, at the base of fleshy or horn}' albumen. 



Herbs, rarely shrubs, occasionally shrubby climbing plants. Leaves 

 alternate, opposite in clematis, variousry divided, without stipules. 



Almost the entire order is characterized by a colorless, acrid, and often 

 poisonous juice. The acrid principle is, however, generally volatile, and 



