136 Scales of the cup (at least the inner ones) with long points 
or awns. Cup usually covering more than half the acorn 
—Bur Oak, Mossy-cup Oak, Over-cup Oak, Quercus macro- 
carpa Mx. 
136 Scales of the cup not awned. Cup usually covering less 
than half the acorn. Southern N. E.—Post Oak, Box 
White Oak, Quercias sldkiia Wang. 
Elm —Leaves simple, alternate, with straight side veins, doubly- 
toothed margins, and unsymmctrical base. Fruit strongly 
flattened, notched at apex, the notch usually closed above, 
and with a broad thin wing surrounding the single seed. 
137 Notch at the apex of the fruit not reaching half way to the 
seed bearing portion—138 
137 Notch at the apex of the fruit reaching more than half way 
to the seed bearing portion—139 
13S Mature fruit % to 1 inch long, surfaces and margins with¬ 
out hairs. Occasionally cult.—Wych Elm, Scotch Elm, 
Ulmw montana With. 
138 Mature fruit about % inch long, seed portion hairy, other¬ 
wise smooth. Ix?af surfaces roughened like line sandpaper 
—Slippery Elm, Red Elm, UlmvH fulca Mx. 
13S Mature fruit *4 to % inch long, slightly hairy all over, and 
densely liairy-fringed along the margins. Northwestern 
N. E.—Cork Elm, Reck Elm, Northern Cork Elm, Ulmw* 
racemom Thomas. 
139 Mature fruit usually not over y z inch long, surfaces smooth, 
margins hairy-fringed. Tree with gradually spreading 
long branches and drooping branchlets—American Elm, 
White Elm, Elm, Ulmw amcricana L. 
139 Mature fruit usually more than y> inch long, surfaces and 
margins without hairs. Main trunk more or less con¬ 
tinuous into the crown. Branches usually short, hori¬ 
zontal, and irregular. Cult. — English Elm, Ulmw 
campcxlris L. 
Mulberry —Leaves alternate, broad, often lobed. Fruit in 
general appearance suggesting a blackberry (except per¬ 
haps in color), though technically quite different. 
