Tkkks ok iiik NokriH'iKN Unitkd Siatks '.»( 



(i. Teeth oi the leaves acute or mucroniilate ; l)ai'k white. 



tiaky ; seed sweet and edible; fruit short peduncled 



or sometimes nearl}- sessile. Q. michauxii. 

 (!. Teeth of the leaves rounded-; bark close; seed edible; 



petioles slender ; peduncles equalling or shorter than 



the petioles. Q. prinus. 

 7. Mature leaves pale, or glaucous and glabrous below. 8. 



7. Mature leaves pubescent or tomentose below, lyrate-pin- 



natilid. 9. 



8. Bark separating in thin scales, light gray or light brown : 



cup shallow ; bracts thick and warty. O. alba. 



8. Bark furrowed and ridged, not scaly, dark gray or dark 



brown ; cup hemispherical, with imbricated, appressed 

 scales ; cultivated in many varieties. Q. robur. 

 n. Leaves pubescent beneath, oblong-obovate, usually 5- 

 lobed, stellate-pubescent above; upper scales of the 

 cup not awned. Q. stcUata. 



9. Leaves white-tomentulose beneath. 10, 



10. Leaves obovate or oblong, lyrate pinnatilid or deeply 

 sinuate-lobed ; upper scales awned, forming a fringe 

 around the acorn. O. macrocarpa. 



10. Leaves ol)Ovate-oblong, deeply 5-9-lobed ; acorn often 



nearly enclosed in the cup. the upper scales not awned. 

 Q. lyraia. 



11. Leaves entire, oblong, linear-oblong or lanceolate. 12. 

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



spatulate in outline. 1'!. 



11. Leaves pinnatitid or pinnately lobed. 14. 



12. Leaves oblong or lanceolate, tomentulose beneath. 0. 



imbricaria. 



12. Leaves linear-oblong, green and glalirous on l)oth sides. 

 Q. phellos. 



l*-{. Leaves spatulate, glabrous on both sides; cup saucer- 

 shaped, acorn globose-ovoid. Q. nigra. 



l-S. Leaves obovate-cuneate. brown-floccose beneath ; cu]) 

 deep, acorn ovoid. Q. marylandica. 



14. Leaves white or gray-tomentose below. 15. 



14. Leaves green on both sides. 17. 



15. Leaf-lobes lanceolate or linear-lanceolate, long ; large 



trees, 10. 



