black oak

FEATURES
The deciduous black oak tree may grow to a height of 80 feet and a diameter of about three and one-half feet. The trunk is straight. The bark is black and deeply furrowed, with a yellow or orange inner bark. The leaves are arranged alternately on the stem. The simple leaf blade has seven to nine shallow lobes, each lobe bristle-tipped. The leaf is dark green, shiny and smooth on the upper surface. It is hairy all over or hairy only along the veins on the lower surface. Each leaf may be 10 inches long and eight inches wide with a five-inch leafstalk. Male and female flowers are separate but located on the same tree. The tiny flower has no petals. Male (staminate) flowers are arranged in drooping clusters, while female (pistillate) flowers are in groups of one to four. The fruit is an acorn. Acorns may be single or in groups of two. The acorn is red-brown, ovoid or ellipsoid and not more than one-half enclosed by the cup. The cup appears to have a ragged edge.

BEHAVIORS
The black oak may be found statewide in Illinois. This tree grows in upland woods. It flowers in April and May when the leaves begin to unfold. The hard, red-brown wood is used in construction, for fuel and for making fence posts.

​Kingdom: Plantae

Division: Magnoliphyta

Class: Magnoliopsida

Order: Fagales

Family: Fagaceae

​common, native