cupuLiFER^. SILVA OF NORTH AMERICA. 



3 



southern New England ten occui\ They then gradually increase southward in numbers^ and in the 

 coast region of the south Atlantic and Gulf states nineteen species are found collected together. This 

 is the greatest aggregation of species in the United States^ although in the central JNIississippi valley 

 Oak-trees are more abundant and grow to a larger size than in any other part of North America. 

 Absent from the high, dry, and cold mid-continental plateau, Quercus reappears on the lower slopes of 

 the southern Rocky Mountains, which are often covered with vast thickets of Qitercus Gamheltiy a 

 species peculiar to the interior of the continent. Farther south this is joined by another species ; and 

 on the mountains of western Texas, southern New Mexico and Arizona, six Oak-trees of the Mexican 

 forests find their northern home. Extremely rare in the arid region between the Rocky Mountains and 

 the Sierra Nevada, where Quercus is represented only by stunted bushes clinging to the upper slopes of 

 the mountain ranges, it is often an important element in the forests nourished by the more humid 

 atmosphere of the Pacific coast, especially in the valleys of central California. Reaching British 

 Columbia and Washington with a single species, the number gradually increases southward, five species 

 occurring in southern Oregon and thirteen in California. 



The type is an early one. The ancestors of existing European species inhabited that continent 

 during the late cretaceous and tertiary periods, ^^ when Quercus was also widely distributed in North 

 America, ranging in the centre of the continent far to the north of its present home, and reaching its 

 fullest development during the upper miocene and the eocene epochs. 



Oak-trees, especially the species of Lepidobalanus with annual fructification, produce strong tough 

 durable timber.^^ The most valuable timber-trees of the genus are the White Oaks and the Live Oak 

 of eastern North America, the European and Asiatic Qitercus Rohur,^^ Quercus Lusitanica^^ of the 



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Mediterranean basin, Quercus dilatata " of the northwest Himalayas, Quercus Griffithii ^ of Sikkim and 



Boutan, and Quercus Mongolica'^ of northeastern Asia. The wood of most of the species makes 

 excellent fuel, and it is often manufactured into charcoal. The tannic acid ^^ contained in the bark of 

 Oak-trees makes that of many species valuable for tanning leather.^^ Among the most useful for this 

 purpose are the European Quercus Rohur, Quercus Cerris,'^'^ Quercus Ilex^^ and Quercus Toza^'^ the 

 eastern American Quercus velutina and Quercus Prinus, and the western American Quercus densi- 

 ora. The large fleshy seeds of some of the species, although slightly astringent, are eaten by man, 

 and are often used for fattening hogs. Those most palatable to man are produced by Quercus Ilex, 

 var. Bcdlota, of the Iberian peninsula and northern Africa, Quercus ^gilops ^^ of the Orient, Quercus 

 Emoryi of the southwestern United States and northern Mexico, and Quercus Miclumxii of the south- 

 eastern United States, although the North American Indians used the acorns of many other species in 

 the eastern ^^ and western ^^ parts of the country. Cork is the bark of Quercus Suher ^^ of the western 

 countries of the Mediterranean basin, and of Quercus occidentalis,^^ an inhabitant of Portugal, Spain, 

 and southwestern France. GaUs caused by the punctures of different insects are produced on the 

 branches of most Oak-trees, and are sometimes important articles of commerce.^^ From a parasitic insect 

 that inhabits the leaves and branches of Quercus coccifera^^ of the Mediterranean basin kermes, a 

 scarlet dye, is obtained. In the United States a decoction of the bark of the young branches of 

 Quercus alba is used in external medicinal appHcations and sometimes internally in the treatment of 

 hemorrhage or dysentery.^^ The bark of Quercus Rohur is employed in medicine as an astringent,^^ 

 and the acorns sometimes supply a tonic and astringent, and a remedy for scrofula.^^ In China and 

 Japan coarse silk'^ is made from the cocoons of larvae fed on the leaves of Quercus Mongolica, 

 Quercus dentata,^^ Quercus serrata,^ and Quercus Bungeana ; *^ and in India a wild silk-worm ^ feeds 

 on the leaves of Quercus incana'^^ of the northwestern Himalaya. From time immemorial Quercus 

 Rohur, the symbol of strength and longevity, has been venerated. It is the great ornament of 

 European parks,^^ and for centuries European foresters have devoted their highest skill to producing 

 the timber of this tree. In the southeastern United States Oaks are largely used to shade city streets 

 and country mansions ;^^ and the groves which surround the temples of southern Japan are chiefly 



