AMERICAN MEDICINAL PLANTS 6 



The medicinal value of botanical drugs depends to a large extent on 

 the time of their collection. Roots from annual plants should gener- 

 ally be dug just before the flowering period; those of biennial and 

 perennial plants should be gathered late in the fall or early in the 

 spring, because during the growing season they are deficient in their 

 active constituents and are of poorer quality generally. Barks also 

 should preferably be collected during the dormant season when the 

 sap is not flowing. Leaves and herbs are of most value when collected 

 during the flowering period or just before they have finished growing. 

 Flowers should always be gathered when they first open. Wherever 

 definite information on these points has been available it has been 

 included in the discussion of the various plants. 



The proper preparation of the collected material is of the utmost 

 importance. If the material contains dirt or other foreign matter, or 

 if it is moldy or has an undesirable color or odor, it may be rejected 

 by the dealers or purchased only at a reduced price. Roots should be 

 thoroughly freed from adhering soil and other dirt. Fibrous roots, 

 or rootstocks with numerous small roots or rootlets, require careful 

 washing to remove such foreign matter. The larger stems of herbs 

 and leaves should be discarded, as they possess little or no value, and 

 leaves that are partly dried from age or that are discolored or injured 

 by disease or insects should be excluded if the best price is to be 

 obtained. 



The material must be carefully dried. All plant material, in what- 

 ever form, is easily spoiled in both appearance and value if improper 

 methods are used to remove the large quantity of moisture that is usu- 

 ally present. Fleshy roots dry very slowly and frequently become 

 moldy unless they are sliced across or lengthwise to permit more rapid 

 evaporation of the moisture. In the drug market such roots occur in 

 various forms, and information on this point should be secured from the 

 dealers or from experienced collectors so that the dried material may 

 conform to market requirements. Leaves readily lose their green color 

 while drying and sometimes become brown or even black. They 

 should, therefore, be spread out in a well-ventilated room, especially 

 in cloudy weather, and dried as rapidly as possible. Exposure to 

 direct bright sunlight is undesirable because it frequently causes 

 bleaching of the leaves. Fruits, particularly those that are juicy, are 

 especially difficult to handle on account of their tendency to become 

 sour or moldy. They should preferably be spread out in thin- layers 

 on wire or cloth screens that will permit a thorough circulation of air 

 and on which they can be frequently stirred. Seeds must be thoroughly 

 cured ; even ripe seeds that appear to be dry will frequently heat and 

 spoil if stored without having been spread out and allowed to dry for 

 at least several days. 



The best way to store the dried material is to pack it in clean bags 

 or boxes. If, however, the material is likely to be injured by exposure 

 to air or light, or if it is subject to the attack of insects, it should be 

 placed in tightly closed cans or other receptacles and marketed at the 

 earliest opportunity. 3 



3 More detailed information on the drying of crude drugs, including also directions for constructing drying 

 rooms and sheds, is contained in Farmers' Bulletin No. 1231, Drying Crude Drugs, which may be obtained 

 free upon request from the O.ffice of Information of the U. S. Department of Agriculture. 



