=C.= Widened near the tip, somewhat obovate and the end usually 3-lobed; bark quite black, smooth or furrowed, but never scaly (Black-oaks). (=F.=) =F.= Leaves acute at base 16. =F.= Leaves abrupt or cordate at base 17. =B.= Leaves distinctly straight-veined, sinuate rather than lobed, the teeth generally rounded and never awned; bark white, rough and scaling (Chestnut-oaks). (=G.=) =G.= Lobes rounded 5, 6, 7. =G.= Lobes rather acute 8, 9. =B.= Leaves coarsely lobed, the lobes usually rounded, never awned; bark white or whitish-brown, cracking and scaling off in thin laminæ (White Oaks). (=H.=) =H.= Leaves crowded at the ends of the branchlets 4. =H.= Leaves not crowded 1, 2, 3. =B.= Leaves more or less lobed, the lobes and teeth acute and bristle-pointed; petiole slender; base rather abrupt; bark dark-colored, smooth or furrowed, but never scaly (Red Oaks). (=I.=) =I.= Leaves smooth both sides, at least when mature 11, 12, 13. =I.= Leaves soft-downy beneath 14, 15. [Illustration: Q. álba.] 1. =Quércus álba=, L. (AMERICAN WHITE OAK.) Leaves short-stemmed, acute at base, with 3 to 9 oblong, obtuse, usually entire, oblique lobes, very persistent, many remaining on the tree through the winter; pubescent when young, soon smooth, bright green above. Acorns in the axils of the leaves of the year, ovoid-oblong, 1 in., in a shallow, rough cup, often sweet and edible. A large tree, 60 to 80 ft. high, with stem often 6 ft. in diameter; wood light-colored, hard, tough and very useful. Common throughout. [Illustration: Q. stellàta] 2. =Quércus stelláta=, Wang. (POST-OAK. ROUGH OR BOX WHITE OAK.) Leaves 4 to 6 in. long, sinuately cut into 5 to 7 roundish, divergent lobes, the upper ones much larger and often 1- to 3-notched, grayish-or yellowish-downy beneath, and pale and rough above. Acorn ovoid, about ½ in. long, one third to one half inclosed in a deep, saucer-shaped cup; in the axils of the leaves of the year. A medium-sized tree, 40 to 50 ft. high, with very hard, durable wood, resembling that of the White Oak. Massachusetts, south and west. [Illustration: Q. macrocárpa.] 3. =Quércus macrocárpa=, Michx. (BUR-OAK. MOSSY-CUP.) Leaves obovate or oblong, lyrately pinnatifid or deeply sinuate-lobed or nearly parted, the lobes sparingly and obtusely toothed or entire. Acorn broadly ovoid, 1 in. or more long, one half to almost entirely inclosed in a thick and woody cup with usually a mossy fringed border formed of the upper awned scales; cup very variable in size, ¾ to 2 in. across. A handsome, middle-sized tree, 40 to 60 ft. high. Western New England to Wisconsin, and southwestward.