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CHAPTER XII 



RELATIONSHIPS OF THE OAKS THEIR DISTRIBUTION 

 IN SPACE AND TIME 



THE oak is a member of a very large and ancient group 

 of dicotyledonous flowering plants, embracing the 

 beeches, chestnuts, hazel-nuts, &c., and many other 

 forest trees of the Northern Hemisphere. 



The number of species of oaks (Quercus) is very 

 large, probably more than 300, of which the majority 

 belong to North America, Europe, China, Japan, and 

 other parts of Asia. There are none in Africa south of 

 the Mediterranean region, nor in South America or 

 Australasia. Some remarkable species are found in the 

 Himalayas, and many in the Malayan Archipelago. 



The various species of the genus Quercus axe 

 arranged into groups according to differences in the 

 form and arrangement of the scales of the cupule, the 

 characters of the leaves, and certain peculiarities in the 

 acorns. Many oaks, especially those of warm countries, 

 for instance, are ' evergreen,' with hard, leathery leaves, 

 quite unlike the leaves of our common British oak. 



