294 SHIMEK: QUERCIS LYRATA IN IOWA 
mately the same as that of the large bottomland form of Q. 
macrocarpa, and a nearby specimen of the latter, recently cut, 
measured 27 inches in diameter and exhibited about 120 rings, 
those from about 55 to 85 showing the most rapid growth. Our 
overcup oak trees are’ probably not less than a hundred years 
old, thus antedating the coming of the white man to this section. 
The trees have been observed both in flower and fruit. Sar- 
gent gives the time of flowering as March or April, but in this 
northern locality the flowers do not appear until about the 
middle of May. 
Two of the trees produce acorns which are entirely enclosed 
in the cup; the third has a partly open cup, a form not infrequent 
in the South. The peduncles of the cups are 6-16 mm. in length. 
The wall of the cup is 3-6 mm. thick or even thicker at the 
base, but thins upward. The scales of the cup are prominently 
tubercular, the tubercles becoming smaller upward. The small 
opening has a short fringe. 
The nut is short-ovate, with a broad basal scar and is 16-19 
mm. in length, with about the same diameter. Its tops and 
sides are covered with a short, grayish pubescence. For cup 
and acorns see PLATE 16, FIG. 2. 
The general aspect of the tree is not unlike that of the large 
form of Q. macrocarpa which grows in somewhat better drained 
spots in the same timber. The latter is here not gnarled or 
stunted, as is usually the case in more exposed localities. It 
is probable that our species has been mistaken for the latter in 
other localities. 
The leaves are distinctly different from those of the nearby 
bur-oaks. As compared with the latter they are thinner, with 
more distinct veinlets; lighter green; more irregularly lobed, 
with the terminal lobe rarely coarsely crenate; usually smaller 
and narrower; and the upper surface is more likely to have scat- 
tered short hairs at maturity, while the pubescence of the lower 
surface is much less dense. PLATE 16, FIG. 3, shows young 
leaves, and PLATE 17 shows mature leaves taken in different 
years. The leaves and acorns shown on the plates are from the 
same tree. 
On the whole the Iowa specimens of Q. lyrata are quite 
typical. ; 
