158 



TREES OF THE NORTHERN UNITED STATES 



Q. imbricaria. 



17. Qu&rcus nlgra, L. (BLACK OAK OR 

 BARREN OAK.) Leaves large, 5 to 10 in. 

 long, thick, wedge-shaped, broadly dilated 

 above, and truncate or slightly 3-lobed at 

 the end, bristle-awned, smooth above, rusty- 

 downy beneath. Acorn oblong-ovate, j to 

 % in. long, in the axils of the leaves of the 

 preceding year, one third or one half in- 

 closed in the top-shaped, coarse-scaled cup. 

 A small tree, 10 to 25 ft. high, with rough, 

 very dark-colored bark. New York, south 

 and west, in dry, sandy barrens. 



18. Qu6rcus imbricaria, Michx. (LAU- 

 REL- OR SHINGLE-OAK. ) Leaves lanceolate- 

 oblong, entire, tipped with an abrupt, 

 sharp point, pale-downy beneath. Acorn 

 globular, 5 / & in. long, cup with broad,whit- 

 ish, close-pressed scales, covering about 

 one third of the nut. A stout tree, 30 to 

 50 ft. high, found in barrens and open 

 woodlands. Wood extensively used in 

 the West for shingles. New Jersey to Wisconsin, and southward. 



19. Qu6rcus Ph611os, L. ( WILLOW-OAK.) 

 Leaves 2 to 4 in. long, thick, linear-lanceo- 

 late, narrowed at both ends, entire or very 

 nearly so, soon smooth, light green, bristle- 

 tipped, willow -like, scurfy when young. 

 Acorns about sessile, globular, small (^ in.), 



in a shallow sau- 

 Q. p&euos. 



cer shaped cup ; 



on the old wood. Tree 30 to 50 ft. high, 

 with smooth, thick bark, and reddish, 

 coarse-grained wood, of little value. 

 Borders of swamps, New Jei-sey, south 

 and west; also cultivated. 



20. Q,u6rcus Robur, L. (ENGLISH 

 OAK.) Leaves on short footstalks, ob- 

 long, smooth, dilated upward, sinuately 

 lobed, hardly pinnatifid. Acorns in the 

 axils of the leaves of the year, ovate-ob- 

 long, over 1 in., about one third inclosed 

 in the hemispherical cup ; sessile in var. 



