Variability of the Acorns of Quercus Macrocarpa. a2 
length in a thick rugged cup, which is generally bordered along its 
upper edge with fine, long flexible filaments. Sometimes, however,” he 
adds, “in compact forests, or in very temperate regions, the filaments 
do not appear, and the edge of the cup is smooth and bent inward.’’* 
Gray says,+ that the cup is “deep, thick and woody, conspicuously 
imbricated with hard and thick-pointed scales, the upper ones awned, 
so as usually to make a mossy fringed border ; acorn broadly ovoid, 
half immersed in or entirely inclosed by the cup. . . . Cup very 
variable, especially in size, from 9’’ to 2’ across.” 
The series of sketches I have prepared illustrate this variability of 
the acorn in a remarkable manner. Figure 1 is the type form with the 
acorn two thirds immersed in the cup, and the latter furnished with a 
delicate fringe on the upper edge. Figure 2 is from a specimen from 
Hardin county,{ Ohio. in which the acorn is almost wholly concealed 
in the cup, and the fringe almost hides it from view. Figure 3 is a 
top view of a widely different form. In this the cup is nearly an inch 
and a quarter across, and the fringe projects at least half an inch all 
round, making it two and a quarter inches in diameter. The acorn 
projects very slightly above the rim of the cup. Figure 4 goes again 
to the other extreme, for here we have a very small acorn, the cup 
slightly fringed, and leaving only a small portion of the apex of the 
nut exposed. In figure 5, we have a cup one and a half inches in 
diameter, in which the fringe has grown down inside the cup, lining 
it all around, and forming a soft bed for the nut to rest on.§ In 
figure 6, we have an acorn in which the cup conceals three fourths of 
the nut, and is almost destitute of any fringe. In figure 7, we have an 
entirely different form again, for here the cup conceals about one half 
the acorn, the walls are very thin, and it is entirely destitute of any 
fringe whatever. Figure 8 represents the variety Oliveformis, Gray, 
from Hardin county, O. Here we see an oblong acorn, with a cup 
half concealing it, and with a very slight fringe. 
Thus we have here eight different looking acorns, all known to be- 
long to the same species, and more than one to be found, perhaps, on 
the same tree. There are all gradations from no fringe at all on the 
*North Am. Sylva, vol. i, p 34. The figure given by Michaux shows the character 
admirably. 
+ Manual, p. 451. 
t This and the following figures are taken from specimens given me by Dr. John A. 
Warder. Specimens from which figs. 2 and 8 were made, were collected by Mr. Hampton of 
Hardin county. 
2 Lhe nut is not shown in the figure, only the cup showing the fringe lining the interior of it. 
