or
more of the acorn --8.

6a. Length of the lateral leaf-lobes less than one-third the width
of the leaf; acorn cup 2-2.5 cm. wide
=Red Oak, Quercus rubra.=

6b. Length of the lateral leaf-lobes more than one-third the width
of the leaf --7.

7a. Acorn depressed-globose, about 1 cm. in diameter
=Pin Oak, Quercus palustris.=

7b. Acorn ovoid, 1.5-2 cm. thick =Schneck's Oak, Quercus schneckii.=

8a. Leaves pubescent beneath =Black Oak, Quercus velutina.=

8b. Leaves glabrous beneath --9.

9a. Buds glabrous; inner bark of the trunk yellow
=Hill's Oak, Quercus ellipsoidalis.=

9b. Buds pubescent beyond the middle; inner bark of trunk red
=Scarlet Oak, Quercus coccinea.=

10a. Leaves deeply pinnately lobed --11.

10b. Leaves crenate, dentate, or sinuate, not lobed --12.

11a. Leaf divided nearly to the middle by a pair of deep lateral lobes
near the middle of the leaf; acorn more than half covered by the
cup =Bur Oak, Quercus macrocarpa.=

11b. Leaf without a median pair of deeper lobes; acorn about one-fourth
covered by the cup =White Oak, Quercus alba.=

12a. Leaves broadest at or near the middle, with numerous (8-13)
sharp coarse teeth on each side
=Yellow Oak, Quercus muhlenbergii.=

12b. Leaves broadest above the middle, with a few shallow, rounded
or subacute teeth (7 or less on each side) --13.

13a. Large tree; leaves densely white-tomentose beneath; acorn on a
stalk 3-10 cm. long =Swamp White Oak, Quercus bicolor.=

13b. Shrub; leaves thinly white-tomentose beneath; acorn sessile or
nearly so =Scrub Oak, Quercus prinoides.=

URTICACEAE, the Nettle Family

Herbs or trees, with small inconspicuous apetalous flowers.

1a. Trees or tall shrubs --2.

1b. Herbs --7.

2a. Leaves oblong-ovate to lanceolate, serrate --3.

2b. Leaves broadly ovate to rotund, some of them lobed (Mulberry)
--6.

3a. Leaves thick, coarsely and doubly serrate, broadest near the middle
(Elm) --4.

3b. Leaves thin, simply serrate, broadest distinctly below the middle