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 sckub-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-tomeutose 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. wade; 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- 

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

 mm. long. — Common, in dry rocky woods. — Chestnut-oak. 



11. Q. bicolor 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. — Svfamp 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 Avith filiform tips ; nuts subglobose or broadly oblong, 30-50 mm. long. — 

 Susquehanna valley and tributary streams. Eare, 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 ease of herbs 

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

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

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

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



