[Illustration: Q. lyràta.] 4. =Quércus lyràta=, Walt. (SWAMP POST-OAK.) Leaves crowded at the ends of the branchlets, very variable, obovate-oblong, more or less deeply 7- to 9-lobed, white-to-mentose beneath when young, becoming smoothish; the lobes triangular to oblong, acute or obtuse, entire or sparingly toothed. Acorn about ¾ in. long, nearly covered by the round, ovate, thin, rugged, scaly cup. A large tree with pale flaky bark. River-swamps in southern Indiana to Wisconsin, and southward. [Illustration: Q. bícolor.] 5. =Quércus bícolor=, Willd. (SWAMP WHITE OAK.) Leaves obovate or oblong-obovate, wedge-shaped at base, coarsely sinuate-crenate, and often rather pinnatifid than toothed, whitish, soft-downy beneath. Main primary veins 6 to 8 pairs. Acorns, nearly 1 in., oblong-ovoid, set in a shallow cup often mossy fringed at the margin, on a peduncle about as long as the acorn, much longer than the petioles of the leaves; in the axils of the leaves of the year. A large tree, 60 to 80 ft. high, stem 5 to 8 ft. in diameter. Most common in the Northern and Western States, in swamps, but found in moist soil in the mountains of the South. [Illustration: Q. Michaùxii.] 6. =Quércus Michaùxii=, Nutt. (BASKET-OAK or COW-OAK.) Leaves 5 to 6 in. long, oval to obovate, acute, obtuse, or even cordate at base, regularly but usually not deeply sinuate, rather rigid, usually very tomentose beneath. Acorn large, 1-1/3 in. long, sweet and edible; cup shallow and roughened with coarse, acute scales; no fringe. A large and valuable Oak with gray and flaky bark. [Illustration: Q. Prìnus] 7. =Quércus Prìnus=, L. (CHESTNUT-OAK.) Leaves obovate or oblong, coarsely undulately toothed, with 10 to 16 pairs of straight, prominent ribs beneath; surface minutely downy beneath, and smooth above. Acorn ovoid, 1 in. long, covered nearly half-way with a thick, mostly tuberculated cup; in the axils of the leaves of the year; kernel sweetish and edible. A middle-sized or small tree, with reddish, coarse-grained wood. Found throughout, but common only southward. [Illustration: Q. Muhlenbérgii.] 8. =Quércus Muhlenbérgii=, Engelm. (YELLOW CHESTNUT-OAK.) Leaves usually thin, 5 to 7 in. long, 1½ to 2 in. broad, oblong-lanceolate, rather sharply notched, mostly obtuse or roundish at base, sometimes broadly ovate or obovate, and two thirds as wide as long. The leaves are usually more like those of the Chestnut than any other Oak; the primary veins very straight, impressed above, prominent beneath. Acorn 2/3 to ¾ in. long, inclosed in a thin, hemispherical cup with small, appressed scales. A middle-sized tree with flaky, pale, thin, ash-colored bark, and tough, very durable, yellowish or brownish wood. Western New England, westward and south. [Illustration: Q. prinoìdes.]