
The pin oak is a large, beautiful tree that grows up to 70 feet tall and can
reach two feet in diameter. It commonly has a strong, upright single stem
with numerous long, tough branches. The lower branches tend to droop, the
middle ones are more horizontal and the upper ones are ascending. This gives
the tree a pyramidal shape, and the many small, bristling twigs and branches
give the tree its name. The pin oak is found widely over the east central
United States. In Iowa it is found in the southeastern part of the state on
rich, moist bottomland soils, along streams and rivers. It is planted widely
for shade and ornamental use.
The leaves of the pin oak are simple, lobed and bristle tipped . They are
smaller and the lobes more deeply cut than the red
oak
leaves with the lobe sinuses reaching almost to leaf mid-vein. They also have
fewer lobes than the black oak leaves. They are
dark green and very shiny above, paler and grayish below, with large tufts
of pale hairs in the axils of the veins.
The young branches are send out short, stiff, spurlike lateral twigs. The fruit is a small acorn, about 1/2 inch long and almost round. The shallowcap of the acorn covers one-third or less of the fruit.
On young stems the bark is smooth, shiny and light brown. On old
large limbs and trunks it is light gray-brown and is covered by small, close
scales.
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