I9I2-] TRELEASE— CLASSIFICATION OF BLACK OAKS. 171 



EXPLANATION OF PLATES. 



In all, the buds are enlarged three diameters, and the acorns and cu- 

 pules are of natural size. No special care has been taken in the selection 

 of material, except to get mature winter buds because the differences are less 

 evident while they are developing, and to pick out average fruits from the 

 varying assemblage presented by each species. 



Plate X. Black Oaks. — i, Qiiercus marilandica ; 2, Q. Catesbcci; 3, Q. 

 digitata; 4, Q. velntina. 



Plate XI. Scarlet Oaks. — i, Qiiercus coccinea; 2, Q. ellipsoidalis ; 3, Q. 

 texana (the northern form known also as Q. Schneckii) ; 4, Q. texana (from 

 Texas) ; 5, Q. rubra; 6, Q. nana. 



Plate XII. Swamp Oaks. — Water Oaks: i, Querciis palustris; 2, Q. 

 nigra; 3, Q. georgiana. Willow Oaks : 4, Quercus imbricaria; 5, Q. Phellos; 

 6. Q. laiirifolia; 7, Q. pumila; 8, Q. brevifolia; 9, Q. myrtifolia. 



Plate XIII. Western Black Oaks. — Olive Oaks : i, Quercus hypoleuca; 

 2, Q. Emoryi. Holly Oaks : 3, Quercus agrifolia; 4, Q. Wislizeni; 5, Q. cali- 

 fornica. 



