35 



ductive function after it has been deprived of roots. Why, in 

 the present case, it did not do this in the first year, rather than 

 in the second, is not clear. Evidently its vigor and resources 

 must have been greater then ; for there could have been no gain, 

 and there must have been some loss. Perhaps it was that unex- 

 plained force which sometimes causes a starved and dying plant 

 to throw all its remaining strength into a final effort for the per- 

 petuation of its species. 



The production of secondary, and quasi-lateral, inflorescences 

 is not uncommon in agaves, both in cultivation and when grow- 

 ing wild. As is well understood, they are produced by offsets, 

 either developed or latent. 

 San Bernardino, California, 

 December 20, 1902. 



A KEY TO THE NORTH AMERICAN SPECIES OF 

 LENTINUS — I 



By F. S. Earle 



The genus Lentinus was founded by Fries in 1825.* From 

 the first it has been an incongruous aggregate consisting ot 

 several groups of quite diverse species which agree only in a 

 certain toughness of texture. In outlining the original generic 

 characters, Fries says the lamellae are concrete with the pileus, 

 while in Agaricus he says they are discrete. This character, 

 however, is shared with Panus, which thus seems to differ only 

 in being still firmer in texture. Many species of Lentinus have 

 the lamellae more or less lacerate or dentate on the margin, but. 

 from the first, species have been included in the genus without 

 this character. 



The genus is now usually divided into the seven following 

 sections : 



Key to the Sections of Lentinus 



I. Stipe central or excentric ; pileus entire. 2. {Mesopodes) 



Stipe lateral or wanting ; pileus dimidiate. Pleuroti. 



Stipe wanting ; pileus resupinate. Resupinati. 



* Syst. Orb. Veg. 77. 1825. 



