Proceedin^^s of the Ohio State Academy of Science 143 



quite immersed in the cup. Wood like in white oak. In swamps. 

 N. J. to Ind., Mo., Fla., and Tex. 



i8. Quercus macrocarpa Mx. Bur Oak. A large tree 

 with flaky gray bark and with a long tap root. Leaves obovate 

 or oblong-obovate, irregularly lobed, pinnatifid, or coarsely cre- 

 nate ; shining above, grayish-white-tomentulose beneath, 4-8 in. 

 long; cup short peduncled or sessile, hemispheric or subglobose, 

 ^-i in. broad, the tips of the bracts forming a fringe around the 

 acorn; acorn ovoid, 1-2 times as high as the cup. Self-prunes 

 abundantly. A very valuable tree with hard and tough wood 

 resembling the White Oak. In rich soil or on river bluffs where 

 it is sometimes small and shrubby. Hybridizes with Q. acumin- 

 ata. N. S. to Man., Mass., Ohio, Kan., and Tex. 



19. Quercus platanoides (Lam.) Sudw. Swamp White 

 Oak. A large tree with flaky gray bark. Leaves obovate, or 

 oblong-obovate, coarsely toothed or sometimes lobed nearly to 

 the middle, dull and glabrous above, densely white-tomentulose 

 beneath ; peduncles of the hemispheric cup 2-5 times as long as the 

 petioles; acorn oblong-ovoid, seed rather sweet. Self-prunes. 

 Wood similar in value to that of the White Oak. In moist or 

 swampy soil. Quebec to Ohio and Mich., Ga., and Ark. 



20. Quercus michauxii Nutt. Cow^ Oak. A large tree 

 with flaky white bark. Leaves obovate or broadly oblong, cre- 

 nately toothed the teeth often mucronulate, 4-8 in. long, cup de- 

 pressed-hemispheric, short-peduncled, i-i^ in. broad; acorns 

 ovoid, about 3 times as high as the cup, sweet and edible. Wood 

 valuable like the White Oak. In moist soil. Del. to Ind., Mo., 

 Ark., Fla., and Tex. 



21. Quercus prinus L. Rock Chestnut Oak. A large 

 tree with brown bark, ridged, close or slightly flaky. Leaves ob- 

 long, oblong-lanceolate, or obovate, coarsely crenate, glabrous 

 above, finely gray-tomentulose beneath, petioles slender ; cup 

 hemispheric, -5-1+ in. broad, peduncles equalling or shorter than 

 the petioles ; acorn ovoid, 2-3 times as high as the cup, seed edible 

 but not very sweet. Self-prunes. Wood hard and strong ; used 

 in fencing and for railroad ties. Bark rich in tannin. In dry 

 soil. Me. to Ont., Ala., Tenn., and Ohio. 



