The occurrence of blackjack oak is said to indicate poor soil since it often occurs on dry or poorly drained, gravelly, clay, or sandy upland soils where few other forest trees thrive. This perhaps accounts chiefly for its slow rate of growth. It is found in those parts of the state that support a natural tree growth, as far west as Callahan County. The tree sometimes reaches a height of 50 or 60 feet and a diameter of 16 inches, but it is usually much smaller. Its hard, stiff, drooping branches form a dense crown which usually contains many persistent dead twigs. The BARK is rough, very dark, often nearly black, and “blocky”; inner bark bright orange or yellow. [Illustration: 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. [Illustration: 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. The WOOD is heavy, hard, and strong, light brown in color, with lighter-colored sapwood. The wood is utilized chiefly for crossties and fuel.