228 TREES OF NORTH AMERICA 



Cup turbinate or hemispherical {sometimes saucer-shaped in C), 



Scales of the cup small, closely appressed ; leaves lustrous, glabrous with 

 the exception of axillary tufts of hairs ; winter-buds glabrous or puberu- 

 lous. 



Leaves oval to obovate-orbicular, deeply 5-7-lobed, dark green and 

 lustrous on the upper surface. 4. Q. ellipsoidalis (A). 



Leaves obovate, truncate or abruptly wedge-shaped at the base, deeply 

 lobed, with broad rounded sinuses, tte lobes sinuate-dentate at the 

 usually broad apex. 5. Q. Texana (A, C). 



Leaves oblong or obovate, deeply lobed, with broad rounded sinuses, 

 the slender lobes coarsely repand-dentate toward the apex, glabrous. 



G. Q. coccinea (A). 

 Scales of the cup large, more or less loosely imbricated, forming a free 

 margin ; leaves usually pubescent below. 



Winter-buds tomentose ; leaves ovate or obovate, slightly or deeply 

 lobed, with broad or narrow nearly entire or dentate lobes, more or 

 less pubescent below. 7. Q. velutina (A, C). 



Winter-buds glabrous or puberulous. 



Leaves oblong or obovate, deeply lobed, the lobes tapering, acute, 

 or broad and obovate at the apex, repand-dentate or entire, gla- 

 brous or pubescent below. 8. Q. Californica (G). 

 Leaves oblong-obovate or triangular, distinctly cuneate, deeply lobed, 

 with acute spreading often falcate lobes, glabrous or rusty-pubes- 

 cent below, short-stalked. 9. Q. Catesbaei (C). 

 Leaves whitish or grayish tomentulose below. 



Leaves mostly acutely 5-lobed, obovate, with short broad lobes. 



10. Q. nana (A). 

 Leaves with elongated mostly falcate lobes. 



Leaves oblong or obovate, fulvous or pale pubescent below, the lobes 

 usually elongated and falcate, or broad and 3-lobed at the apex. 



11. Q. digit ata (A, C). 



Leaves oval to oblong, deeply 5-11-lobed, the lobes acuminate, mostly 



falcate, white -tomentose below. 12. Q. pagodaefolia (A, C). 



Leaves widening upward, often abruptly dilated at the broad sinuate or 



obscurely 3-5-lobed apex. 



Leaves broadly obovate, rusty-pubescent below. 



1.3. Q. Marilandica (A, C). 

 Leaves obovate-spatulate or narrowly wedgershaped, glabrous. 



14. Q. nigra (C). 

 I I I I Leaves lanceolate to oblong or lanceolate-obovate, usually entire, involute in the 

 bud. Willow Oaks. 

 Leaves glabrous. 



Leaves lanceolate, narrowed and acute at the ends. 



15. Q. Phellos (A, C). 



Leaves oblong to oblong-obovate, dark green and lustrous above, 



somewhat paler below. 10. Q. laurifolia (C). 



Leaves tomentulose or pubescent below, oblong-lanceolate to oblong-obovate. 



Leaves pale blue-green, coated below with hoary tomentum. 



17. Q. brevifolia (C). 

 Leaves dark green and lustrous above, pubescent below. 



18. Q. imbricaria (A). 

 - -i-Leaves persistent until the appearance of those of the following year, revolute in 

 the bud {involute in 21). 



Leaves lanceolate, oblong-lanceolate or elliptical, entire or spinose- 



