The Oaks 



The wood of the tan-bark oak is used for fuel, but has little 

 lumber value. Its bark, however, is more valuable to the tanner 

 than any other. So the tree is threatened with extinction by the 

 irresponsible bark peelers, and by forest fires carelessly set. 



This tree grows along dry hillsides and in mountain ravines 

 in California and Oregon, keeping along the coast range, and 

 flourishing especially among the redwoods. Government pro- 

 tection of the latter would save from utter annihilation another 

 remnant of former times, for the tan-bark oak is scarcely less 

 interesting to the botanist than the redwood itself. 



2. Genus QUERCUS, Linn. 



I. THE WHITE OAK GROUP 



Acorns annual; leaf lobes rounded; bark usually pale. 



KEY TO SPECIES 



A. Pacific coast species. Deciduous. 



B. Foliage blue with silvery lining. (Q. Douglasii) blue oak 

 BB. Foliage green. 



C. Acorns slenderly conical ; branchlets slender, pendu- 

 lous; leaves white lined. 



{Q. lobata) California white oak 

 CC. Acorns oval; branchlets stout, erect; leaves not 

 white lined. (Q. Garryana) pacific post oak 



AA. Eastern species. 



B. Foliage evergreen. (Q. Virginiana) live oak 



BB. Foliage semi-persistent, blue, (Q,. hreviloha) durand oak 

 EBB. Foliage deciduous. 



C. Leaves pinnately lobed by deep sinuses. 



D. Under sides of leaves smooth. {Q. alba) white oak 

 DD. Under sides of leaves downy. 



E. Branches corky; acorn large, in fringed cup. 



{Q. macrocarpa) bur oak~ 

 EE. Branches not corky; acorn medium in size. 

 F. Acorn globose, enclosed by scaly cup. 



{Q. lyrata) overcup oak 

 FF. Acorn ovoid, half hid in scaly cup; leaf 

 lobes and sinuses broad, squarish. 



{Q. minor) post oak 

 CC. Leaves sinuately dentate with shallow sinuses; 

 linings pale, downy. 



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