ULMACEAE (ELM FAMILY) 



8 a Cup with scales compressed about the top; inner bark 



not yellowish-orange SCARLET OAK. (Q. coccinea.) 



b Cup with scales more or less reflexed about the top ; 

 inner bark yellow or orange, very bitter 



BLACK OAK. (Q. velutlna.) 



9 a Bark on trunk furrowed, dark gray 10 



b Bark on trunk flaky, light gray 12 



10 a Cup of acorn much fringed; leaves usually regularly 



lobed; cultivated species TURKEY OAK. (Q. cerris*) 



b Cup of acorn not fringed u 



n a Leaves with regularly lobed margin; cup enclosing 

 about % or less of nut; native species 



ROCK CHESTNUT OAK. (Q. prtnus.) 

 b Leaves variously lobed; cup enclosing ^ or more of nut; 



cultivated species ENGLISH OAK. (Q. pedunculata.*) 



12 a Lobes of leaves short, the indentations extending about 



}4 distance to midrib; cup with stalk 2-4 in. long; 

 bark very loose on branchlets 



SWAMP WHITE OAK. (Q. platanoldes.) 

 b Trees not completely as in a 13 



13 a Lobes of leaves usually much narrower toward the base, 



often relobed at apex; leaves usually with brownfeh 



hairs beneath POST OAK. (Q. minor.) 



b Leaves not completely as in a 14 



14 a Cup conspicuously fringed at top, mossy; tree not com- 



mon BUR OAK. (Q. macrocarpa.) 



b Cup not fringed at top ; tree common 



WHITE OAK. (Q. alba.) 

 6 URTICALES. Nettle Order. 



i ULMACEAE. Elm Family. 

 i ULMUS. 



1 a Leaves not noticeably rough on upper surface; buds 



not hairy WHITE ELM. (U. Americana.) 



b Leaves rough above except when old; buds hairy 2 



2 a Native tree; branches usually slender and drooping; 



inner bark mucilaginous to the taste, especially in the 



spring; leaves 3-8 in. long SLIPPERY ELM. (U, fulva.) 



b Cultivated tree; branches rather coarse, ascending or 

 horizontal; inner bark not mucilaginous to the taste; 



leaves 2-4 in. long ENGLISH ELM. (U. campestris*) 



2 C&LTIS HACKBERRY. (C. occidentalis.) 



2 MORACEAE. Mulberry Family. 

 i M6RUS. 

 i a Mature leaves dull green above, often rough ; fruit 



purplish RED MULBERRY. (M. rubra.) 



b Mature leaves usually shining and smooth above; fruit 



whitish WHITE MULBERRY. (M. alba*) 



144 



