142 Proceedings of the Ohio State Academy of Science 



nate, about ^ in. broad ; acorn subglobose, bitter. A\'ood poor ; 

 used for shingles and clapboards. Self-prunes twigs by means 

 of basal joints. 0. leana Xuft. is a hybrid of this and Q. velu- 

 tina. Q. tridentata Engelm. is a hybrid with 0. uiarylandica. 

 Also hybridizes with 0. palustris and 0. rubra. Pa. to Alich., 

 Neb., Ga., Ark., and Ohio. 



15. Quercus alba L. White Oak. A large tree with 

 light gray bark scaling oil in thin plates. Leaves obovate, pin- 

 natifid, lobes oblong, toothed or entire ; cup depressed-hemi- 

 spheric, its bracts thick and warty, appressed ; acorn ovoid-oblong, 

 3-4 times as high as the cup, sweet and edible. Autumn leaves 

 red and russet. Self-prunes extensively. Wood light-colored, 

 hard and tough ; valuable for many purposes ; an ideal wood for 

 railroad ties; used for poles, posts, -and piling, for fuel and "acid 

 wood," for cooperage, furniture, interior finishing lumber, farm 

 implements, wharves, ship building, and car and wagon work. 

 The most valuable of the American oaks. Hybridizes with 0. 

 uiacrocarpa, O. minor, 0. frijius, and 0. acuminata. Ale. to 

 Ont., Minn., Fla., Kan., Tex., and Ohio. 



*. Quercus robur L. English Oak. A large strong tree 

 with stout more or less spreading branches forming a broad 

 round-topped head ; self-prunes. Alany forms are cultivated for 

 ornament, including yellow-leaved and cut-leaved varieties, also 

 forms with varied branches. Native of Europe. 



16. Quercus minor (Marsh.) Sarg. Post Oak. A shrub 

 or usually a small tree with a long tap root and with rough gray 

 bark and valuable wood. Leaves broadly obovate, deeply lyrate- 

 pinnatifid, glabrous above, brown-tomentulose beneath, 4-8 in. 

 long ; cup hemispheric, nearly sessile ; acorn ovoid, 2-3 times as 

 long as the cup, very sweet. In dry soil. Mass. to Ohio and 

 Mich., Fla., and Tex. 



17. Quercus lyrata "Walt. Overcup Oak. A large tree 

 with gi"ay or reddish bark in thin plates. Leaves obovate, lyrate- 

 pinnatifid or lobed to beyond the middle 6-8 in. long, shining 

 above, densely white-tomentulose beneath, cup depressed-globose, 

 peduncled, i-i| in. broad; acorn depressed-globose, nearly or 



