ANGIOSPERM TREES 



289 



large size, great durability, and ease of reproduction (by stump 

 sprouts) made it a favorite for many uses. The large, edible nut 

 was formerly roasted and sold in considerable quantities. There 

 is good reason to believe that a disease-resistant hybrid (resulting 

 from a cross with the Japanese chestnut) will be developed, but 

 replacement as a forest species, if 

 possible, will be far in the future, 

 since the place of dominance 

 once held by American chestnut 

 in the eastern forests has been 

 taken over by other species, 

 many of them inferior in value. 



The Oaks 



The OAKS (Quercus) constitute 

 by far the largest group of hard- 

 wood trees in the world. They 

 number between two and three 

 hundred species, and many more 

 if hybrids are included; sixty of 

 these attain tree size in the 

 United States. The alternate 

 leaves are either deciduous or 

 evergreen, and extremely variable in size and shape, often on 

 the same tree. The leaf margins exhibit a wide variety of 

 characteristics, being deeply or shallowly lobed, notched, toothed, 

 or smooth. The buds, both terminal and laterals, are character- 

 istically clustered at the ends of the twigs. Male flowers are 

 borne in drooping catkins; the female solitary or in few flowered 

 spikes which give rise to the fruit, an acorn or nut pardy enclosed 

 by a scaly cup. 



In addition to being the largest group, the oaks are by far the 

 most important group of hardwoods in North America. Annually 

 they furnish more native timber than any other group of broad- 

 leaved trees, being surpassed only by the conifers. In addition to 

 their wood being of great value, the bark of certain species is 

 important as a source of tannins, and the world's cork supply is 

 )roduced by two European oaks. From the standpoint of their 



Fig. 206. — Ghestntus have 

 sharply-toothed pointed leaves and 

 rounded nuts in large prickly burrs. 



