138 Proceedings of the Ohio State Academy of Science 



6. Inner bark orange; leaves sometimes lobed to beyond the middle; 

 acorn ovoid, more or less longer than the cup. Q. velutina. 



6. Inner bark gray or reddish; leaves deeply lobed. 7. 



7. Leaves dull and paler beneath; acorn ovoid. Q. borealis. 



7. Leaves shining on both sides, lobed to near the mid-rib; acorn 



ovoid ; cup I" in. wide, more or less. Q. ellipsoidalis. 



8. Leaf-lobes lanceolate or linear-lanceolate, long; large trees. 9. 



8. Leaf-lobes triangular-ovate, short; shrubs or low trees. Q. nana. 



9. Leaves rounded or obtuse at the base, 3-5 lobed; lobes linear or 



lanceolate, often falcate. Q. digitata. 

 9. Leaves cuneate or acute at the base, 5-11-lobed; lobes triangular. 



Q. pagodaefolia. 

 10. Leaves obovate-cuneate, brown-floccose beneath; cup deep, acorn 

 ovoid. Q. marylandica. 



10. Leaves spatulate, glabrous on both sides; cup saucer-shaped, acorn 



globose-ovoid. Q. nigra. 



11. Leaves linear-oblong, green and glabrous on both sides. Q. phellos. 



11. Leaves oblong or lanceolate, tomentulose beneath. Q. imbricaria. 



12. Leaves pinnatifid or pinnately lobed. 13. 



12. Leaves crenate or dentate, not lobed. 17. 



13. Mature leaves pale, or glaucous and glabrous below. 14. 



13. Mature leaves pubescent or tomentose below, lyrate-pinnatifid. 15. 



14. Bark separating in thin scales, light gray or light brown; cup shal- 



low ; bracts thick and warty. Q. alba. 



14. Bark furrowed and ridged, not scaly, dai'k gray or dark brown; 



cup hemispherical, with imbricated, appressed scales ; cultivated 

 in many varieties. Q. robur. 



15. Upper scales of the cup not awned. 16. 



15. Upper scales awned, forming a fringe around the acorn. O. macro- 



carpa. 



16. Leaves yellowish-brown, tomentulose beneath; acorn ovoid. Q. 



minor. 



16. Leaves white-tomentulose beneath; acorn depressed-globose. Q 



lyrata. 



17. Fruit peduncled ; teeth or shallow lobes of the leaves rounded. 18. 



17. Fruit sessile or nearly so; teeth or shallow lobes of the leaves 



acute. 20. 



18. Peduncle much longer than the petioles; leaves white-tomentulose 



beneath. Q. platanoides. 



18. Peduncle as long or shorter than the petioles; leaves gray-tomen- 



tulose beneath. 19. 



19. Bark white, flaky; seed sweet and edible; fruit short peduncled or 



sessile. Q. michauxii. 

 19. Bark close; seed edible; petioles slender; peduncles equalling or 

 shorter than the petioles. Q. prinus. 



