MEDICINAL PLANTS 



OF 



NOliTlI AMERICA. 



PH^NOGAMOUS OR FLOWERING PLANTS. 



CL.iSS I. — DICOTYLEDONOUS OR EXOGENOUS PLANTS. 



Stems with bark, wood, and jntli tlistinct ; wlien 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 lives or 

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

 a whorl. 



Division I. — Polypetalous Exogenous Piants. 



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

 genera and species. Petals each separate and. distinct. 



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RANUNCULACE/E. 



Gharacler 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 som(;timcs 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, distiiict. 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 horny albumen. 



Herbs, rarely shrubs, occasionally shrubby climbing plants. Leaves 

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



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

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



