380 Fagaceae Quercus 



the largest and widest; the under surface usually yellow green and more or 

 less densely pubescent with fascicled hairs, rarely with some tomentum, the 

 upper surface often with straggling hairs; nuts mostly less than 12 mm in 



diameter at maturity 7. Q. stellata. 



Branchlets glabrous at the end of the season or only sparsely pubescent; leaves 



mostly obovate in outline, rarely oblong, cut into 5-9 lobes; blades white- to 



gray-tomentose beneath, or those of lower branches often green and 



pubescent beneath; nuts more than 12 mm in diameter. 



Upper scales of cup awned, forming a fringe about the cup; blades mostly 



1-2.5 dm long, generally deeply lobed or pinnatifid; nuts very large, rarely 



nearly covered by the cup; vigorous one year old branches sometimes 



corky 8. Q. macrocarpa. 



Upper scales of the cup not awned but sometimes the upper scales forming 

 a ragged rim about the top, which should not be mistaken for awned 

 scales; nut usually covered or almost so by the cup; leaves generally 



much smaller than those of the preceding species 9. Q. lyrata. 



Mature leaves with bristle tips; fruit maturing the second year; inner surface of shell 

 of nut tomentose; bark dark, tight, and furrowed. (The Black Oaks.) 



Leaves entire (rarely a seedling or coppice shoot with some toothed leaves) 



10. Q. imbricaria. 



Leaves more or less deeply lobed, the lobes and teeth conspicuously bristle-pointed. 



Mature leaves smooth beneath, except for tufts of hairs in the principal axils (rarely 



some of the leaves of no. 16 glabrous). 



Lateral lobes of all leaves (measured along the upper side from the tip to the 



base of the sinus) about as long as, or slightly longer than, the undivided 



portion of the blade. 



Cup flat on the bottom, shallow (saucer-shaped); blades not lustrous above. . . . 



11. Q. borealis var. maxima. 



Cup rounded on the bottom. 



Scales at the top of the cup closely appressed. (Should be sought in Indiana.) 



Q. borealis. 



Scales at the top of the cup loosely imbricated, their free tips forming 

 a fringelike border; terminal buds large, grayish-pubescent, generally 



somewhat 4-sided; blades lustrous above 12. Q. velutina. 



Lateral lobes of leaves (measured along the upper side from the tip to the base 

 of the sinus) usually much longer than the undivided portion of the blade 

 (lower leaves of no. 14 often not cut so deeply); blades lustrous above. 

 Cup flat or only slightly convex on the bottom, shallow (saucer-shaped), 

 usually covering about a fourth of the nut. 



Cup thin, usually less than 1.6 cm broad 13. Q. palustris. 



Cup thick, more than 1.6 cm broad (fruit resembling that of no. 11) 



14. Q. Shumardii. 



Cup strongly convex on the bottom, usually covering more than a fourth to 



about half of the nut. 



Scales at the top of the cup loosely imbricated, their free tips forming 



a fringelike border, generally gray-pubescent all over, never tuberculate 



on the back; inner bark yellow; buds large, 4-sided, gray-pubescent.... 



12. Q. velutina. 



Scales at the top of the cup all closely appressed (in dried specimens some- 

 times becoming more or less loose) ; buds generally glabrous or nearly 

 so, generally not so large and rarely 4-sided; lower scales usually 

 glabrous but the upper generally pubescent. 



Cup covering a fourth to a third of the nut 



14a. Q. Shumardii var. Schneckii. 



Cup covering about half of the nut. 



Inner bark yellowish or orange; nut generally ellipsoidal; kernel of nut 

 yellowish or orange and very bitter 15. Q. ellipsoidalis. 



