FAGACEAE. 335 



12. Quercus nigra L. Water Oak. (I. F. f. 1236.) Bark gray, rough in 

 ridges. Leaves spatulate or obovate, 1-3-lobed at the apex, or some of them entire 

 and rounded, coriaceous, short-petioled, rather bright green and shining, finely 

 reticulate-veined, glabrous when mature except tufts of hairs in the axils of the 

 veins beneath, 3-8 cm. long, the lobes low, usually obtuse and bristle-tipped; styles 

 recurved; cup saucer-shaped with a rounded base, 10-14 mm > broad, its bracts 

 appressed; acorn globose-ovoid, 2-3 times as high as the cup. Along streams and 

 swamps or sometimes on the upland, Del. to Ky., Mo., Fla. and Tex. April-May. 

 Acorns ripe Sept.-Oct. [Q. aquatica Walt.] 



13. Quercus Phellos L. Willow Oak. (I. F. f. 1237.) A tree, with 

 slightly roughened reddish brown bark. Leaves narrowly oblong or oblong- 

 lanceolate, entire, acute at both ends, very short-petioled, bristle-tipped, glabrous 

 Dr very slightly pubescent in the axils of the veins beneath when mature, 5-10 cm. 

 long, 8-25 mm. wide ; styles slender, recurved-spreading; cup saucer-shaped, 

 nearly flat on the base. 8-12 mm. broad; acorn subglobose, 8-12 mm. high. In 

 moist woods, L. I. to Fla., Mo. and Tex. April-May. Acorns ripe Sept.-Oct. 



Quercus heterophylla Michx., the Bartram Oak, probably a hybrid of Q. Phellos 

 frith Q. rubra, but perhaps a distinct species, intermediate in leaf and fruit characters 

 between the two, occurs from Staten Island to X. Car. and in Mo. Q. Phellos hybrid- 

 izes also with Q. nan.i. 



14. Quercus Iaurifdlia Michx. Laurel Oak. (I. F. f. 1238.) Bark 

 nearly black, with flat ridges. Leaves oblong or oblong-obovate, often somewhat 

 falcate, green and shining above, paler beneath, glabrous when mature, 0.3-1.5 

 cm. long. 1-2.5 cm. wide, entire, or those of young shoots undulate-lobed, the 

 apex bristle -tipped; styles rather short, recurving; cup saucer-shaped, 8-12 mm. 

 wide, its base somewhat rounded, its scales ovate, rounded, appressed ; acorn 3-4 

 times as long as the cup. Along streams and swamps, Va. to Fla. and La., mostly 

 near the coast. 



15. Quercus imbricaria Michx. Shingle Oak. (I. F. f. 1239.) A forest 

 tree. Leaves oblong or lanceolate, entire, coriaceous, acute at both ends, short- 

 petioled. bristle- tipped, dark green above, persistently gray-tomentulose beneath, 

 0.7-1.7 dm. long, 1.5-5 cm - wide; styles recurved; cup hemispheric or turbinate, 

 10-14 mm. broad, its bracts appressed; acorn subglobose, 10-14 mm. high. Cen- 

 tral Penn. to Mich., Neb., Ga. and Ark. April-May. 



Quercus Leana Xutt. is a hybrid of this and Q. velutina, with intermediate char- 

 acters. Ohio to Mo. and D. C. 



Quercus tridentata Engelm. is a hybrid with Q. Marylandica. 111. and Penn. 

 Also hybridizes with Q. palnstris and Q. rubra in Mo. 



16. Quercus alba L. White Oak. (I. F. f. 1240.) A large forest tree, with 

 light gray bark scaling off in thin plates. Leaves obovate, green above, pale and 

 more or less glaucous beneath, pubescent when young, nearly glabrous when old, 

 thin, pinnatifid into 3-9 oblong obtuse-toothed or entire lobes, 1-2 dm. long; styles 

 short, erect; fruit peduncled; cup depressed-hemispheric, 1.4-2 cm. broad, its 

 bracts thick, warty, obtuse, woolly or at length glabrate, appressed; acorn ovoid- 

 oblong, 2.5 cm. high or less, 3-4 times as high as the cup. Me. to Out., Minn., 

 Fla. and Tex. May-June. Acorns ripe Sept.-Oct. 



Hybrids with Q. macrocarpa have been observed in 111., with Q. minor, from 111. to 

 Va. and S. Car., with Q. Prinus, near Washington, D. C, and N. Y., and with Q. acu- 

 minata in Mo. 



17. Quercus minor (Marsh.) Sarg. Post or Iron Oak. (I. F. f. 1241.) 

 A tree, with rough gray bark, or sometimes a shrub. Leaves broadly obovate, 

 deeply lyrate-pinnatifid into 3-7 broad rounded often deeply undulate or toothed 

 lobes, when mature firm, glabrous, dark green and shining above, brown-tomentu- 

 lose beneath, 1-2 dm. long. 1-1.5 dm. wide or smaller; petioles stout; fruit nearly 

 or quite sessile; styles short; cup hemispheric, 12-16 mm. broad, base narrowed, 

 i f s bracts lanceolate, subacute, slightly squarrose; acorn ovoid, 1-2 cm. high, 2-3 times 

 is long as the cup. In dry soil, Mass. to S. N. Y. , Mich., Fla. and Tex. May- 

 June. Acorns ripe Sept.-Oct [Q. obtusiloba Michx.j 



