PREFACE XI 



may not be on hand. Inasmuch as the common names of the 

 plants lead to many mistakes and much confusion, it is indis- 

 pensable to acquaint one's self with the description of the plant 

 and be sure that the actual product conforms in all respects to 

 the description. For this purpose it is well to obtain flowering 

 specimens, and bearing this fact in mind I have been careful to 

 indicate the flowering season of each plant. By making ex- 

 cursions to the towns of San Mateo and Angono I have ob- 

 tained an abundance of whatever I sought and at the same time 

 have learned by talking with the mountaineers and " curande- 

 ros," what uses they make of their plants. The " curanderos " 

 know a great deal concerning these uses, but become very 

 reticent as soon as they are questioned about them. Whether 

 it is dread of ridicule or selfishness or fear that silences them, 

 the fact remains that it is no easy matter to glean any useful 

 facts from them. And yet by tact and friendliness one may 

 elicit much more information from them than first impressions 

 would lead one to hope. 



Leaves should be gathered when fully developed, rejecting 

 the old, dried and worm-eaten ones. 



The best time to gather bark is one month before the period 

 of inflorescence, when it is rich in sap. The flowers are best 

 gathered when about half expanded. The fruit is gathered 

 green or ripe according to the active principle sought. The 

 seeds should always be mature. 



Not all parts of the plant are equally provided with the 

 active principle which may be localized in the root or the 

 flower ; or distinct principles may exist in different parts of the 

 same plant. Therefore the part indicated, and only that part, 

 should be employed. 



In the root the active substance usually resides in the bark, 

 sometimes in the parenchyma that envelopes the woody tissue 

 and rarely in the woody tissue itself, as, for example, in " rhu- 

 barb " and " pareira brava." 



