100 FAGACEAE. 



7. Q. nana (Marsh.) Sarg. Shrub rather intricately branched, or tree becoming 

 7 m. tall: leaf -blades obovate or oval in outline, 6-12 cm. long, with white or 

 pale-gray tomentum beneath, pinnatifid into 3-5 triangular or deltoid lobes: 

 acorns short-stalked or nearly sessile; cup saucer-shaped (or shallow-turbinate), 

 14-18 mm. wide; nut ovoid-globose or depressed, 10-15 mm. long. S. Com- 

 mon, on dry hills. Schists, serpentine. BEAR-OAK. BLACK SCRUB-OAK. 



8. Q. prinoides Willd. Shrub, or tree becoming 6 m. tall: leaf -blades obovate 

 or oblanceolate, or rarely nearly oblong, 5-15 cm. long, coarsely toothed, 

 cuneate or rarely rounded at the base, finely gray-tomentose beneath: acorns 

 sessile or nearly so; cup hemispheric, 13-18 mm. wide; nut oblong-ovoid, 15-25 

 mm. long. S. Not very common, dry hills. Schists. SCRUB CHESTNUT- 

 OAK. 



9. Q. Muhlenbergii Engelm. Tree becoming 50 m. tall, the bark scaly: 

 leaf -blades lanceolate to oblong-lanceolate, 5-20 cm. long, coarsely serrate, with 

 usually somewhat flaring teeth, minutely pubescent beneath or glabrate: acorns 

 sessile or nearly so; cup hemispheric, about 15 mm. wide; nut ovoid, about 15 

 mm. long. CHESTNUT-OAK. YELLOW-OAK. 



10. Q. Prinus L. Tree becoming 30 m. tall, the bark close : leaf -blades oblong 

 to oval, varying to broadest slightly above or below the middle, 15-20 cm. 

 long, coarsely crenate-serrate, gray-tomentulose beneath: acorns short - 

 peduncled; cup hemispheric, 12-35 mm. wide; nut ovoid or oblong-ovoid, 25-35 

 mm. long. Common, in dry rocky woods. CHESTNUT-OAK. 



11. Q. tricolor Willd. Tree sometimes becoming 36 m. tall: leaf -blades 

 obovate to oblong-obovate, 5-20 cm. long, coarsely toothed or shallowly lobed, 

 usually cuneate at the base, densely white-tomentose beneath: acorns long- 

 stalked; cup saucer-shaped or depressed-hemispheric, 20-25 mm. wide, with 

 some of the bracts prolonged; nut oblong or oblong-ovoid, 20-25 mm. long or 

 slightly longer. S. Common, in low grounds. Schists. SWAMP WHITE- 

 OAK. 



12. Q. macrocarpa Michx. Tree becoming 55 m. tall: leaf -blades obovate to 

 spatulate in outline, 10-30 cm. long, finely tomentose beneath the pinnate 

 lobes, spreading, the terminal lobe largest and usually coarsely crenate: acorns 

 long-stalked; cup deep-hemispheric or globular, 20-40 mm. wide, the upper 

 scales with filiform tips ; nuts subglobose or broadly oblong, 30-50 mm. long. 

 Susquehanna valley and tributary streams. Bare, on shaded banks. OVER- 

 CUP-OAK. MOSSY-CUP OAK. BUR-OAK. 



13. Q. stellata Wang. Tree becoming 30 m. tall: leaf -blades broadly 

 obovate in outline, 10-20 cm. long, finely tomentose beneath with gray or yel- 

 lowish hairs, pinnatifid into usually broad diverging lobes: acorns often clus- 

 tered; cup hemispheric and contracted at the base, 15-20 mm. wide; nut ovoid, 

 15-20 mm. long. S. Common, in dry soil. Schists, serpentine. POST-OAK. 

 IRON-OAK. 



14. Q. alba L. Tree becoming 45 m. tall: leaf -blades obovate in outline, 10-20 

 cm. long, glaucous and finally glabrous beneath, pinnatifid into 3-9, usually 7, 

 ascending narrow lobes: acorns short-stalked; cup saucer-shaped or shallow- 

 hemispheric, woody-tuberculate, 15-20 mm. wide; nut oblong-ovoid, 15-25 mm. 

 long. Common, in woods. WHITE-OAK. 



Order URTICALES. 



Shrubs or trees, or herbs. Leaves alternate, or in the case of herbs 

 often opposite : blades simple, entire, toothed, or divided. Flowers various, 

 not in aments. Calyx present. Corolla wanting. Androecium often of 

 as many stamens as there are sepals. Gynoecium of a single carpel or of 

 2 united carpels. Fruit an achene, a samara, a drupe, or a syncarp. 



