Submit. North America is home to many oak trees. Oaks are easily distinguished by their lobed leaves and their unique seeds, the acorns. Acorns are hard, round seeds that can range, depending on the tree, climate and location, from 3/4 inch in diameter to over 1 inch in diameter.Acorns are rounded with a sharp tip.heir trunks can be several feet in diameter. The bark of the white oak is ashen-gray or white. On younger trees, the bark is scaly or platy, but older trees can have smooth areas of bark. White oak is most common at the east of the Mississippi river.