10. Q. rubra L. Red Oak. (Q. borealis Michx.). A tree 20-30 m. high, 1-2 m. in diameter, the bark smooth, greenish-brown, on older stems broken into flat-topped ridges separated by narrow fissures; inner bark reddish; twigs glabrous; buds red, more or less hairy, about 5 mm. long; acorn 2-3 cm. long, narrowly ovoid or ellipsoid, the cup shallow, saucer-shaped. Upland woods, Prince Edward Island to Minnesota and Nebraska, south to Georgia and Oklahoma (Fig. 72).
11. Q. palustris Muenchh. Pin Oak. A tree 15-40 m. high, 6-9 dm. in diameter, easily recognized in winter by the drooping lower branches; twigs brown, glabrous; buds obtuse, brown, 3-4 mm. long; acorn globose or depressed, 1-1. 5 cm. long, the cup flat, saucer-shaped, enclosing the nut only at the base. Bottomlands, Massachusetts to Michigan and Iowa, south to North Carolina, Louisiana, and Oklahoma (Fig. 73).
12. Q. coccinea Muenchh. Scarlet Oak. A tree 20-30 m. high, with a trunk diameter of 6-9 dm.; bark of the trunk rough, gray, the inner bark reddish; twigs glabrous; buds more or less silky, brownish-red, 5-6 mm. long; acorn 1. 3-2 cm. long, subglobose or short-ovoid, usually with a few concentric rings about the apex; cup hemispherical, with a conical base. Dry soil, Maine to Ontario, south to Georgia, Mississippi, and Oklahoma (Fig. 74).
13. Q. shumardii Buckl. Shumard Oak. A large tree 30-45 m. high, 1-2 m. in diameter; bark on old trees very thick, broken into pale scaly ridges by deep darker colored furrows; buds 5-6 mm. long, ovoid, downy or glabrous; acorn 2-3 cm.long, oblong-ovoid; cup thick, shallow, the scales appressed. Bottomlands, most common on and near the coastal plain, Texas to Florida and Maryland, north in the Mississippi - Ohio Valley to Iowa and West Virginia (Fig. 75).
14. Q. velutina Lam. Black Oak. A tree 15-35 m. tall, the trunk 6-12 dm. in diameter; outer bark very dark brown, rough in low ridges, the inner bark bright orange-yellow; buds large, 7-10 mm. long-hairy, angular; acorn ovoid to hemispherical 1. 2-2 cm. long, light brown, often pubescent; cup hemispherical. Dry woods, New Hampshire to Minnesota, south to Florida and Texas (Fig. 76 ).
Fig. 75. Quercus shumardii.
Fig. 76. Quercus velutina.
Fig. 77. Quercus falcata.
Fig. 78. Quercus ilicifolia.
15. Q. falcata Michx. Spanish Oak. Southern Red Oak. A tree 20-35 m. high, 6-9 dm. in diameter; bark black with broad scaly ridges; buds almost blood-red, more or less silky; acorn 1-1. 5 cm. long, the nut enclosed only at the base by the saucer-shaped cup. Moist woods, most common on or near the coastal plain, Texas to Florida and Pennsylvania, north in the Mississippi-Ohio Valley to Missouri and West Virginia (Fig. 77 ).
16. Q. ilicifolia Wang. Scrub Oak. A straggling shrub or low tree 1-10 m. high, often forming dense thickets; twigs glabrous; buds 4 mm. long, glabrous; acorn globose-ovoid, 1-1.2 cm.long, the cup saucer-shaped. Barrens, Maine to New York, south mostly in the mountains to West Virginia and North Carolina (Fig. 78 ).
17. Q. marilandica Muenchh. Blackjack Oak. A tree 10-15 m. high, 3-4. 5 dm. in diameter; bark black, very rough and blocky; twigs scurfy-puberulent; buds large, brown, angled; acorn ovoid, 1.5-2.5 cm. long; cup deep, the bracts appressed, pubescent. Dry soil, Florida to Texas, north to Maryland, New York, Illinois, and Nebraska (Fig. 79 ).
18. Q. imbricaria Michx. Shingle Oak. A tree 8-27 m. high, 3-9 dm. in diameter; bark with shallow fissures, the ridges with brown scales; twigs brown, glabrous; buds brown, 3 mm. long, pubescent; acorn subglobose, 1-1.4 cm. high; cup hemispheric, the bracts appressed. Bottomlands, New Jersey to Wisconsin and Nebraska, south to South Carolina and Kansas (Fig. 80 ).