BLACKJACK OAK (Twig, two-thirds natural size; leaf and [fruit], one-third natural size)
The LEAVES are [deciduous], tawny-pubescent, of leathery texture, dark green on the upper surface, lighter underneath, broadly wedge-shaped, and variable in shape, 4 to 10 inches long and about the same in width. The [FRUIT] is an acorn about ¾ inch long, yellow-brown and often striped, enclosed for half its length or more in a thick, light-brown cup. The acorns mature at the end of the second season; flesh of cotyledons yellow.
The WOOD is heavy, hard and strong. It is used for firewood and is made into charcoal.
WATER OAK
Quercus nigra L.
Water oak is native along the borders of swamps and streams and on rich bottomlands in Texas as far west as the Colorado River. It has been widely planted along streets and in parks as a shade tree. When fully grown this tree reaches a height of about 80 feet and a diameter exceeding 1 to 3 feet. The [BARK] is smooth, light brown tinged with red, and has many smooth, thin [scales] over the surface. Water oak can be best distinguished from the willow oak—a close associate, but longer-lived—by the differences in the general shape and size of leaves.
WATER OAK (Leaf, one-third natural size; twig and [fruit], one-half natural size)
The LEAVES are [simple], quite variable in shape, mostly [oblong], broader near the point, and more narrow at the base, giving a wedge-shaped effect, often slightly three-lobed at the outer end, thin, and of a dull bluish-green color, paler below than above; mostly smooth, and usually 2 or 3 inches long and 1 to 2 inches wide; remain green for some time, then turn yellow and gradually fall from the tree during the winter.
The FLOWERS appear in April when the leaves begin to unfold. The [FRUIT], an acorn, matures at the end of the second season. The acorn is from ½ to ⅔ inch long and nearly as broad, light brown or yellowish-brown and often striped, enclosed at the base only in a thin saucer-shaped cup.