82 KEY TO GENERA AND SPECIES 



much like those of the American 

 Chestnut, except at the variable 

 base.) Native in Eurasia and 

 Africa. European Chestnut, Cas- 

 tanea sativa Mill. 



NOTE. Certain Japanese Chestnuts (Fig. 

 149) are occasionally cultivated 

 within our range; these can usu- 

 ally be recognized by the very 

 large bur, sometimes 4 or more 

 inches in thickness, also by the small 

 but prominently bristle-tipped teeth 

 of the leaf margin, and the rounded or 

 often auriculate base of the blade. 



Fig. 149. 

 Japanese 

 Chestnut. 



OAK. Leaves simple, alternate. Fruit a nut sur- 

 ** . rounded at the base by a cup composed of 



closely overlapping scales ; commonly known 



as an acorn. 

 126. Leaves without lobes or marginal teeth 127. 



126. Leaves either lobed or toothed, or both 128. 



127. Mature leaves of fruiting branches usually an 



inch or more wide near the middle, and 

 about 3 times as long as broad.* Perm. 



* Some leaves may occasionally be somewhat lobed. 



