CULTIVATION OF MEDICINAL PLANTS. 737 



The method for producing new varieties is by hybridization, 

 or cross-pollination, of different related species or varieties (Fig. 

 403). The offspring is known as a hybrid, and has a blending of 

 the qualities or characters of the two parent plants. This method 

 is. mostly employed by florists who desire to produce some new 

 or striking flower, or by horticulturists who desire to establish 

 some new quality or transfer a desirable quality from a foreign 

 plant to one which is adapted to a given locality. The method 

 has not been largely employed in the cultivation of medicinal 

 plants, except in the case of cinchona, where it is claimed that the 

 barks richest in alkaloids are the direct result of hybridization 

 and selection. By transplanting and special methods of treat- 

 ment, as that of mossing, the alkaloidal percentage has been in- 

 creased from 8' per cent, to 10, whereas by hybridization the 

 amount of total alkaloids has reached as high as 16 per cent., about 

 three-fourths being quinine. 



Collecting and Drying of Drugs. — The time of the collec- 

 tion of vegetable drugs is of prime importance, and, while it 

 may not be possible to make extended generalizations, still, the fol- 

 lowing rules for the collection of various drugs may be given : 



(i) Roots, rhizomes, and barks should be collected immedi- 

 ately before the vegetative processes begin in the spring, or 

 immediately after these processes cease, which is usually in the 

 fall. 



(2) Leaves should be collected when photosynthetic processes 

 are most active, which is usually about the time of the develop- 

 ment of the flowers and before the maturing of fruit and seed. 



(3) Flowers should be collected prior to or just about the 

 time of pollination. 



(4) Fruits should be collected near the ripening period, i.e., 

 full grown but unripe. 



(5) Seeds should be collected when fully matured. 



It should be emphasized that these are very general rules for 

 the guidance of the collector, and that when one is farming drug 

 plants this question becomes exceedingly vital, as not only do the 

 constituents vary at dift'erent times during the season, but there 

 is considerable variation in the amount of drug obtained. The 

 exact information regarding the proper time of gathering any 

 47 



