ipiS-l 



OF EASTERN NORTH AMERICA. 



173 



garetta, regarded by some as a good species, but which has often 

 been regarded as an alba-minor hybrid, suggests such a relationship, 

 but this is more or less doubtful. 



The clearest and most highly differentiated group is that of the 

 chestnut oaks. It may be connected with the more typical forms 

 through forms such as bicolor (shape of leaf) and lyrata (bud-scales) , 

 That the serrate leaf is secondarily derived, through a lobed form, 

 and not a persistence of the serration found in older portions of 

 the genus is perhaps not proven; the tendency to lobation rather 

 than serration on young shoots, as well as the general relation of 

 the chestnut oaks to the other oaks of this region make it, however, 

 highly probable. 



MUHLENBERGll GROUP 



MARGARETTA 



The above diagram may make more concrete these suggestions 

 concerning relationships. 



