Black oak's specific name (velutina) derives from the Latin word for fleece. It refers to the leaves that are densely downy
(hairy) when young. Mature leaves are very dark yellowish-green and shiny on the upper side, with 5-7 bristle-tipped lobes.
Black oak can easily fool people because the lower shade leaves and the upper sun leaves look very different. Lower leaves
are usually large and very wide at the apex. They can be irregularly lobed with shallow sinuses between the lobes, or hardly
lobed at all. The sun leaves at the top of the crown are smaller, with very deep u-shaped sinuses. Black oak bark is uniformly
furrowed all along the trunk forming irregular small plates and is very dark gray (black). The inner bark contains a yellow
pigment called
quercitron, which was sold commercially in Europe until the 1940s. Native Americans used black oak to treat a wide variety of ailments
including indigestion, chills, and fevers. It was also used as an antiseptic. This tree produces reliable acorn crops every
2-3 years. Acorns are readily consumed by insects, squirrels, mice, voles, white-tailed deer, and wild turkey. Trunk cavities
in live black oaks were important nest sites for the northern flicker on Nantucket Island. Gypsy moth, an introduced invasive
species, defoliates black oak, and 2-3 successive defoliations can kill a tree.