117 



Balbiviana Small and in one of the southwestern oaks, Quercus 

 fusiformis Small. It is interesting to note in this connection that 

 in certain of our common oaks {Quercus rubra L., Q. palustris 

 DuRoi, Q. coccinea Wang., and Q. velutina Lam.) while vivipary, 

 in the exact sense, has not been observed, nevertheless in these 

 germination commences immediately upon the fruit reaching the 

 ground in the autumn. 



Vivipary, it seems, is by no means the unusual condition it 

 has generally been supposed to be. 



Teachers College, Columbia University. 



A KEY TO THE NORTH AMERICAN SPECIES OF 

 RUSSULA— II * 



By F. S. Earle 



Section 3, Rigidae 



Pileus dry, smooth, glabrous, f 



Pileus pruinose, furfuraceous, areolate, etc. 



Pileus white or tinted. 

 Pileus deep red or bright red. 



Taste mild; pileus often rose-tinted. 

 Taste acrid ; pileus pure ivory-white. 



Stipe white or reddish-white ; pileus cinnabar-red, acrid. 

 Stipe blood- red ; pileus blood-red or purplish-red. 



Pileus pure white, then alutaceous, rivulose. 



Pileus yellow, paler with age, slightly mealy. 



Pileus grayish-brown, pulverulent or scurfy. 



Pileus cinnamon, rimose, then floccose. 



Pileus greenish, areolate. 



Pileus rose-red. 



Pileus changeable, often dingy purple when young. 



Pileus with disk lighter, whitish, rimose-scaly. 

 Pileus with disk darker, pulverulent, shining. 



Lamellae white ; pileus areolate. 



Lamellae yellow ; spores yellow ; pileus silky- squamulose 



2. 

 5- 



3- 

 4- 



R. albella Pk. 

 R. albidida Pk. 



R. rub?-a Fr. 

 R. Linnaei Fr. 



R. lactea ( Pers. ) Fr. 



R.jlavida Frost 



R. pulverulenta Pk. 



R. cinnamomta Bann. 



R. virescens ( Schaeff. ) Fr. 



6. 



7- 



R. lepida Fr. 



R. Mariae Pk. 



R. cutifracta Cke. 

 R. ohvacea Fr. 



* Continued from page 103. 



f Some of the species assigned to section Rigidae are glabrous and perhaps should 

 be excluded. 



