B. p. I.— 669. 



AMERICAN MEDICINAL LEAVES AND HERBS. 



INTRODUCTION. 



Less difficulty will be encountered in the collection of leaves and 

 herbs than in the case of other portions of plants, for not only is 

 recognition easier, since, especially in the matter of herbs, these 

 parts are usually gathered at a time when the plants are in flower, 

 but the labor is less arduous, for there are no roots to dig or barks 

 to peel. 



Of the three dozen medicmal plants mentioned in this bulletin, 15 

 are recognized as official in the Eighth Decennial Revision of the 

 United States Pharmacopoeia. This is more than half of all the 

 leaves and herbs included in the Pharmacopoeia. 



Among the plants included in this bulletin are peppermint and 

 spearmint, which are found not only in the wild state but the culti- 

 vation of which for the distillation of the oil constitutes an impor- 

 tant American industry. Especially is this true of peppermint? 

 thousands of acres being devoted to the cultivation of this plant, 

 prmcipally in the States of Michigan and New York. A number of 

 other plants mentioned in this paper furnish usefid oils, such as oil 

 of wintergreen, pennyroyal, fleabane, tansy, wormwood, and fire- 

 weed. 



As in the case of other bulletms of this series, an effort has been 

 made to include in it only such plants as seem most in demand, lack 

 of space forbidding a consideration of others which are or have been 

 used to a more limited extent. With two or three exceptions the 

 illustrations have been reproduced from photographs taken from 

 nature by Mr. C. L. Lochman. 



COLLECTION OF LEAVES AND HERBS. 



Leaves are usually collected when they have attained full develop- 

 ment and may be obtained by cutting off the entire plant and strip- 

 ping the leaves from the stem, using a scythe to mow the plants 

 where they occur in sufficient abundance to warrant this, or the 

 leaves may be picked from the plants as they grow in the field. 

 Wlienever the plants are cut down in quantity they must be care- 

 fully looked over afterwards for the purpose of sorting out such 

 5l9 7 



