GENUS 3. 



BEECH FAMILY. 



623 



18. Quercus lyrata Walt. Overcup or Swamp 

 Post Oak. Fig. 1531. 



Quercus lyrata Walt. Fl. Car. 235. 1753. 



A large tree, maximum height about 100 and trunk 

 diameter 3^ ; bark gray or reddish, in thin plates. 

 Leaves obovate in outline, mostly narrowed at the base, 

 6'-8' long, lyrate-pinnatifid or lobed to beyond the 

 middle, thin, when mature bright green, glabrous and 

 shining above, densely white-tomentulose or becoming 

 glabrate beneath, the lobes lanceolate or oblong, rounded 

 or subacute, entire or toothed, the upper pair the larger 

 and usually divergent; petioles 3"-9' long; fruit matur- 

 ing the first season, peduncled; styles short; cup de- 

 pressed-globose, i'-ii' in diameter, i'-l' high, its bracts 

 broad, thin, cuspidate; acorn depressed-globose, i'-ii' 

 high, nearly or quite immersed in the cup. 



In swamps or along streams, New Jersey to Indiana and 

 Missouri, Florida and Texas. Wood hard, strong, tough, 

 close-grained, very durable, dark brown ; weight per cubic 

 foot 52 Ibs. April-May. Water white-oak. 



19. Quercus macrocarpa Michx. Mossy-cup, Blue or Bur Oak. Fig. 1532. 



Q. macrocarpa Michx. Hist. Chen. Am. 2. pi. 23. 1801. 

 Q. olivacformis Michx. f. Hist. Arb. Am. 2 : pi. 2. 1812. 



A large tree, with gray flaky bark ; maximum 

 height about 160, and trunk diameter 8. 

 Leaves obovate or oblong-obovate in outline, 

 rather thin, irregularly lobed, pinnatifid, or some 

 coarsely crenate; when mature bright green and 

 shining above, grayish-white-tomentulose be- 

 neath, 4'-8' long, the lobes toothed or entire, 

 rounded, ascending or somewhat divergent; 

 petioles i'-i' long; fruit short-peduncled or 

 sessile, maturing the first season ; styles short ; 

 cup hemispheric or subglobose, 8"-2' in diameter, 

 its bracts floccose, thick, hard, ovate or lanceolate, 

 the lower acute, the upper subulate-tipped, the 

 tips forming a fringe around the acorn ; acorn 

 8"-ii' long, ovoid, 1-2 times as high as the cup. 



In rich soil, Nova Scotia to Manitoba, Wyoming, 

 Massachusetts, Georgia, Kansas and Texas. Wood 

 hard, strong, tough, close-grained ; color dark brown ; 

 weight 46 Ibs. Mossy-cup white-oak. Scrub-oak. 

 May-June. 



20. Quercus bicolor Willd. Swamp White Oak. Fig. 1533. 



Q. Prinus platanoides Lam. Encycl. 1 : 720. 1783. 



Quercus bicolor Willd. Neue Schrift. Ges. Nat. Fr. Berlin, 

 3: 396. 1801. 



Q. platanoides Sudw. Rep. Secy. Agric. 1892 : 327. 1893. 



A large tree, with flaky gray bark ; maximum 

 height about 110 and trunk diameter 9. Leaves 

 obovate, or oblong-obovate, coarsely toothed or 

 sometimes lobed nearly to the middle, narrowed or 

 rounded at the base, firm, when mature 4'-? long, 

 3i'-4^' wide, dark green, dull and glabrous above, 

 densely white-tomentulose beneath ; petioles stout, 

 3"-9" long; fruit maturing the first year; peduncles 

 2-5 times as long as the petioles; cup hemispheric, 

 its bracts pubescent, lanceolate, appressed, the lower 

 obtuse, the upper acute or acuminate ; acorn oblong- 

 ovoid, about I high ; cup about 6" high ; seed rather 

 sweet. 



In moist or swampy soil, Quebec to Minnesota, Georgia 

 and Arkansas. Wood hard, strong, tough, close-grained, 

 light brown ; weight 48 Ibs. per cubic foot. Swamp-oak. 

 May-June. Acorns ripe Sept.-Oct. 



