112 Bulletin 194 



SUMMER KEY TO THE SPECIES OF QUERCUS 



a. Leaves deeply cut or lobed. 



b. Leaf-lobes acute, bristle-tipped; fruit maturing in the second 

 season. 



i\ Lower surface of leaves more or less pubescent; buds hoary- 



tomentosc; bark of trunk deeply furrowed and scaly; inner 



bark yellow; nut >^-^ inch long, inclosed for about one-half 



of its length by a deep, turbinate cup! . . .Q. velutina, p. 127. 



cc. Lower surface of leaves glabrous or nearly so; buds glabrous; 



bark of trunk smoothish or only slightly fissured ; inner bark 



whitish or pinkish ; nut about 1 inch long, inclosed only at 



the base by a shallow, saucer-shaped cup. .Q. rubra, p. 125. 



bb. Leaf-lobes rounded, not bristle-tipped; fruit maturing in the 



first season. 



c. Leaves cut nearly to the midrib by a pair of deep sinuses near 

 the middle of the leaf ; branches corky-ridged ; nut usually 

 }i-\y2 inches long, deeply seated in a large, conspicuously 



fringed cup Q. macrocarpa, p. 117. 



cc. Leaves not cut by a pair of deep sinuses; branches not corky- 

 ridged ; nut about ^4 "i^l^ lo^g^ about one-fourth inclosed by 



a thin, tomentose, warty cup Q. alba, p. 115. 



aa. Leaves not deeply cut nor lobed. 



b. Bark on branches breaking into large, papery scales which curl 

 back; acorns on stems 1-4 inches long; tree typical of swamps. 



Q. bicolor, p. 119. 

 bb. Bark on branches close, not breaking into large, papery scales ; 

 acorns sessile or on stalks less than 1 inch long; trees not typical 

 of swamps. 



c. Bark of trunk thin, not deeply fissured into inverted V-shaped 

 ridges, flaky, silvery gray or ash colored ; leaves coarsely 



toothed Q. muhlenbergii, p. 121. 



cc. Bark of trunk thick, deeply fissured into inverted V-shaped 

 ridges, not flaky, dark red-brown to nearly black ; leaves 

 coarsely crenate Q. prinus, p. 123. 



