78 
IOWA ACADEMY OF SCIENCE 
The parent oaks in this case are easily distingui’shed by the following char- 
acters : 
Q. palustris DuRoi. 
Young leaves : 
Lower surface quite densely pubescent, 
with more prominent tufts of hairs 
in the axils of the large veins. 
Upper surface with few reddish-brown 
or purplish club-shaped trichomes. 
Margins red, not thickened, not revolute. 
Petioles short. 
Mature leaves : 
Quite regularly 5 to 7-lobed, each lobe 
long bristle-pointed. 
Rather thin. 
Veins rather distinct, the midrib pro- 
jecting above both the upper and 
lower surfaces. 
Margin scarcely revolute, and not thick- 
ened. 
Lower surface smooth, except for tufts 
of hairs in axils of veins. 
Blade 4 to 6% inches long and 4 to 5% 
inches wide. 
Petioles 1 to 2 inches long, smooth. 
Flowers : 
Stigmas recurved or spreading, terete, 
red. 
Staminate flowers with calyx of 4 or 5, 
mostly unequal, broad, often irregu- 
larly slightly lobed sepals, with la- 
ciniate margins, and without abruptly 
tapering apex. 
Fruits : 
Cup very flat below, shallow, covered 
with closely appressed tomentum 
within. 
Acorns sub-spherical or even depressed 
at apex, and often showing slight 
longitudinal ribs or angles. 
Q. imbricaria Michx. 
Young leaves : 
Lower surface more densely pubescent, 
without special prominent tufts in 
the axils of the large veins. 
Upper surface with numerous reddish- 
brown or purplish club-shaped tri- 
chomes. 
Margins green, thickened, distinctly rev- 
olute. 
Petioles long, often nearly equal to 
blade. 
Mature leaves : 
Entire, or somewhat 3-lobed, and some- 
times irregularly repand-lobate on 
young shoots. 
More leathery. 
Veins more prominent, the midrib in 
a groove above, at least in its lower 
half. 
Margin usually distinctly thickened, 
and somewhat revolute. 
Lower surface quite uniformly pubes- 
cent. 
Blade 3% to 4% inches long, and 1 to 
1% inches wide. 
Petioles % to % inch long, pubescent. 
Flowers : 
Stigmas short, yellowish-green. 
Staminate flowers with calyx of 4, 
mostly equal, lance-ovate, entire sep- 
als, with abruptly tapering tips which 
are laciniate-tufted at the apex. 
Fruits : 
Cup somewhat obconical or turbinate, 
somewhat deeper, the scales rather 
loose, especially toward margin of 
cup, and its inner surface nearly 
smooth. 
Acorns more conical, and terete. 
With special reference to the characters here brought out the hybrid may 
be described as follows: 
In general aspect and habit it resembles both parents, which are very 
similar in this respect. 
The young leaves have the lower surface densely tomentose, without promi- 
nent tufts in the axils of the large veins, resembling Q. imbricaria. In other 
respects the young leaves are intermediate, having margins somewhat revolute, 
slightly thickened, and in part red, especially toward the base, and with medium 
petioles. In division of blade the young leaves are also intermediate between 
the parent species. 
The mature leaves vary from quite entire to deeply lobed, the sinuses ex- 
tending fully half way to the midrib. The lobes are rounded or acute, more or 
less spreading or , curved outward at apex, and when distinct terminating in a 
long bristle point, as in Q. palustris. From one to three lobes may appear on 
each side, and they are usually unequal and irregular. In texture they re- 
semble Q. palustris, but the venation is intermediate in prominence and the 
midrib rises to the level of the upper surface, or is sometimes slightly depressed 
in an imperfect groove at the base of the blade. The margin is somewhat 
thickened and sometimes slightly revolute. The lower surface is smooth except 
for tufts of hairs in most of the axils of large veins and occasional patches of 
scant pubescence, especially toward the base of the blade. The blades vary in 
