pin oak Fagaceae Quercus
Leaf: Alternate, simple, 3 to 6 inches long, oval in outline with 5 to 9 bristle-tipped lobes and irregularly deep sinuses that extend nearly to the midrib. Major lobes form a U-shape. Bright green above and pale below with axillary tifts.
Flower: Species is monoecious; male flowers borne on slender, drooping yellow-green catkins; females reddish green borne on short spikes in new leaf axils, appearing in the spring with the leaves.
Fruit: Acorns are 1/2 inch long, striated, round (but flattened at the cap); thin and saucer-like cap, covered with red-brown appressed scales; matures after 2 years, dispersed fall to early winter.
Twig: Slender, red-brown in color and quite lustrous with multiple terminal buds that are small, pointed, and chestnut brown.
Bark: Gray-brown and very tight and thin; remains smooth for many years, eventually develops thin ridges and furrows.
Form: A medium sized tree that is very pyramidal; lower branches are pendulous and middle branches grow at right angles; branches are studded with numerous branchlets that do not prune readily, resulting in a spiny appearance.
Looks like: scarlet oak - Nuttall oak - black oak - northern pin oak