338 NEW ENGLAND TREES IN WINTER. 



Key to Oaks based upon fruiting material. 



109. Fruit maturing in autumn of second year, ripe acorns therefore 

 borne upon parts of twig two years old; immature acorns to be 

 found in winter on twigs of the past season's growth; shell of 

 nut hairy inside; abortive ovules at the top of the nut; scales 

 of acorn-cup broad and thin; lobes of leaves bristle-pointed ....... 



................................................. Black Oaks 110 



109. Fruit maturing in one year, ripe acorns therefore borne upon past 

 seasons growth; no immature acorns to be found upon twigs in 

 winter; shell of nut smooth inside; abortive ovules at base of nut; 

 lower scales at least of acorn cup more or less thickened at base 

 giving a knobby appearance to surface of cup; scales more or less 

 densely woolly; kernel commonly sweetish; lobes of leaves not 

 bristle-pointed; bark flaky except in Chestnut Oak ............. 



................................................. White Oaks 114 



110. Cup of acorn shallow saucer-shaped .......................... Ill 



110. Cup top-shaped .............................................. 112 



111. Cup thin, 15 mm. or less wide; buds 4 mm. or less long ........... 



................................. Pin Oak (Quercus patustris) p.448 



111. Cup thick, 20 mm. or more wide; buds over 4 mm. long ........... 



.................................... Red Oak (Quercus rubra)p.44Q 



112. Buds under 4 mm. long; twigs slender; shrubs ..................... 



................................. Bear Oak (Quercus ilicifolia) p.454 



112. Buds over 4.5 mm. long; twigs rather stout; trees ............ 113 



113. Upper scales of cup loosely overlapping; buds pointed, whole 

 surface woolly; inner bark yellow. Black Oak (Quercus velutina}j?.452 



113. Upper scales of cup closely overlapping; buds blunt, downy above 

 middle; inner bark pale red. Scarlet Oak (Quercus coccinea) p.450 



114. Upper scales of cup with thread-like outgrowths forming a 

 fringe to cup; branchlets often with corky ridges; lateral buds 

 frequently appressed ........ Bur Oak (Quercus macrocarpa) p.436 



114. Cup without distinct fringe; branchlets without corky ridges; 

 jiateral buds divergent , , ..................... . ............... 115 



115. Bark on branchlets peeling back in dark stiff-papery layers; 

 marginal scales of cup narrow awn-pointed; acorns long-stalked. 

 ........................ Swamp White Oak (Quercus bicolor)v.4S8 



115 Bark on branchlets not peeling back in dark stiff-papery layers; 

 acorns sessile or short-stalked (at times long-stalked in White 

 Oak) ....................................................... 116 



116. Buds sharp-pointed 

 116. Buds blunt 



117. Nut 20-35 mm. long; buds 4-10 mm. long; bark thick, furrowed, 

 not flaky .................... Chestnut Oak (Quercus Prinus)V.444 



117. Nut 15-20 mm. long; buds 3-6 mm. long; bark thin, flaky. 



....................... Chinquapin Oak (Quercus Muhlenberg^^j.440 



118. Twigs slender, generally not over 2 mm. thick; shrubs ......... 



.................... Dwarf Chinquapin Oak (Quercus prinoides)v.442 



118. Twigs relatively stout, generally over 2 mm. thick; trees ---- 119 



119 Twigs, at least in part, covered with very fine close olive-green 

 down; buds, generally nearly hemispherical, about as broad as 

 long; scales of cup only slightly knobby, apex of nut generally 

 downy ........................ Post Oak (Quercus stellata) p.434 



119. Twigs' smooth; buds distinctly longer than broad, broadly ovate; 

 scales of cup thick-knobby at base, apex of nut generally smooth. 

 ................................. White Oak (Quercus alba) p.432 



Key to Oaks without fruit. 



NOTE. (W) after name indicates that the tree belongs to the White 



Oak Group. 

 (B) after name indicates that the tree belongs to the Black 



Oak Group. 



Immature acorns therefore may often be found on winter twigs of 

 species marked with (B) but not on those marked with (W). 



120. Buds large, those at tip of twig 4.5 mm. or more long ........ 121 



120. Buds smaller, less than 4.5 mm. long ........................ 1*8 



