The Oaks 



279 



Inner scales of cup inflexcd; southern tree. 

 Inner scales of cup not inflcxed. 



Inner bark of tree bright orange; leaves mostly 



hairy, at least on the veins. 

 Inner bark gray to reddish or yellow; leaves green 

 beneath. 

 Leaves dull, not shining, paler beneath; northern 



tree. 

 Leaves shining above. 

 Cup 10 to 15 mm. broad. 



Cup top-shaped; nut ellipsoid to subglobose; 



northern tree. 

 Cup hemispheric; nut oblong; Texan tree. 

 Cup 15 to 25 mm. broad. 



Cup much wider than high; eastern tree. 

 Cup about as wide as high; western tree. 

 Leaves white-tomentulose or gray-tomentulose beneath; 

 eastern trees. 

 Large trees; leaf-lobes mostly long, lanceolate. 

 Leaves rounded or obtuse at base, 3- to 7-lobed. 

 Leaves cuneate, acute or truncate at the base; 5- to 

 13-lobed. 

 Small tree or shrub; leaf-lobes triangular, short. 

 Leaves 3- to 5-lobed above the middle or entire, obovate or 

 spatulate in outline. 

 Cup hemispheric; leaves obovate, brown hairy beneath. 

 Cup saucer-shaped; leaves spatulate to obovate, smooth. 

 Cup shallow; nut over 10 mm. long; leaves thick. 

 Cup deep; nut less than 10 mm. long; leaves thin, 

 tt Leaves entire or rarely with a few teeth toward the apex, linear 

 to elliptic or oblanceolate; Willow oaks. 

 Leaves smooth beneath. 

 Cup very flat. 

 Leaves sharp-pointed, linear-oblong to narrowly elliptic. 

 Leaves blunt, oblong to cuneate-oblong. 

 Cup with a narrow base, saucer-shaped; leaves shining 

 above. 

 Leaves hairy beneath. 



Leaves brown hairy beneath; cup mostly hemispheric. 

 Leaves gray-hairy beneath; cup saucer-shaped. 

 ** Leaves persistent. 



Leaves densely white downy beneath; southwestern tree. 

 Leaves green beneath, smooth when mature. 



Nut long, narrowly ovoid; cup deep; California tree. 

 Nut short, ovoid; cup shallow; southeastern tree, 

 b. Fruit maturing the first season; leaves persistent; leaves oval to orbic- 

 ular, convex; California tree. 

 B. Leaves lobed or entire, rarely bristle tipped; styles very short or none; 



shell of nut mostly smooth inside; White oaks. 

 a. Fruit maturing the second season; leaves persistent. 



5. Q. Calesbcet. 



6. Q. velulina. 



Q. borealis. 



8. Q. ellipsoidalis. 



9. Q. texana. 



10. Q. coccinea. 



11. Q. Kelloggii. 



12. Q. triloba. 



13. Q. pagodcpjolia. 



14. Q. ilicijolia. 



15. Q. marylandica. 



16. Q. nigra. 



17. Q. microcarya. 



