CHAPTER XXVII: THE OAKS 



Family pAGACEyE 



Genera PASANIA and QUERCUS 



Trees of great lumber and horticultural value. Leaves sim- 

 ple, alternate, entire or lobed. Flowers monoecious, inconspicuous ; 

 staminate, in pendulous catkins; pistillate, solitary or few in a 

 cluster. Fruit, a dry nut in a scaly cup (an acorn). 



KEY TO GENERA AND GROUPS 



A. Plowers of two sorts borne in the same cluster an erect, 

 crowded spike; leaves evergreen, chestnut-like. 



I. Genus Pasania, Orst. 

 AA. Flowers of two sorts borne in separate clusters; staminate in 

 pendant catkins; pistillate, few or solitary on short stalks. 



2. Genus Quercus, Linn. 

 B. Fruit annual; leaves with rounded lobes, not spiny 

 pointed; bark usually pale. The White Oak Group 

 BB. Fruit biennial; leaves with lobes spiny pointed; bark 

 usually dark. The Black Oak Group 



The oaks form one of the largest and noblest of the tree 

 families. There are 300 species recognised by botanists, and this 

 probably does not include them all. They are distributed widely 

 over the continents of the Northern Hemisphere, and follow the 

 mountains through Central America and across the equator along 

 the Andes. All but a very few species are large trees, important 

 features of the landscape and the commerce of the countries in 

 which they grofw. Among broad-leaved trees they hold a pre- 

 eminent place, and have held it from ancient times, in house and 

 naval architecture and in bridge building. In durability, strength 

 and toughness oak has few superiors. 



Fifty species of oak are native to America; half of them dis- 

 tributed in the Eastern and mid-Continental regions, half on the 

 Western slopes. The backbone of the continent, the main chains 



190 



