CHAPTER XIII 



The Oak and Chestnut 



The family to which the oak and the chestnut belong is now called 

 the Fagaceae and includes the beech as well as various other tree 

 types not familiar to the residents of the United States. The beech 

 has been discussed in a separate chapter, and the present chapter 

 will be devoted to the oak and chestnut after some mention is 

 made of these other genera. The first of these is one called Casta- 

 nopsis wliich has about 30 existing forms with evergreen leaves and 

 found from the Himalayas and tropical India to Hong Kong, and 

 represented on our Pacific coast. Castanopsis is intermediate 

 between the true oaks and the chestnut, and its presence on both 

 shores of the Pacific indicates that its ancestors must have flourished 

 in the intermediate country and over the land bridge connecting 

 North America and Asia in the Behring Sea region at some past 

 time when the climate of these northern lands was more genial than 

 it is today. Pasania is a second genus of existing oak-like plants 

 with over 100 species in the southeastern Asiatic region, and hke 

 Castanopsis, it is represented on our Pacific coast by a single form 

 which ranges from southwestern Oregon to southern Cahfornia, 

 separated from its 100 Oriental congeners by the whole breadth 

 of the Pacific ocean. This western form is the so-called Tanbark 

 oak, the Quercus densifolia of Hooker and Arnott. 



There seems to be no doubt but that all of these and the other 

 members of the oak family are the diversified descendants of a com- 

 mon Cretaceous stock. This ancestral stock is represented by the 

 extinct genus Dryophyllum which is first recognized in the Upper 

 Cretaceous at which time it was not only abundant and varied 

 but widespread. Its leaves were of the chestnut, entire or holly 

 oak type, and possessed a characteristic arrangement of the veins 

 which usually enables them to be readily recognized and distin- 

 guished from those of the oak, chestnut or beech. They were 



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