ULMACEAE 71 



3. Q. velutina Lam. BLACK OAK. Leaves as in Q. Texana but 

 usually pubescent below along the veins even when mature, and 5-sided 

 in outline, sometimes smooth : cup hemispheric, its scale somewhat squar- 

 rose, yellowish floccose-pubesceut : acorn 6"-12" long, about twice the 

 length of the cup. A common tree, especially in the southern part. 

 April-May. A form, common especially in the southern part, with 

 leaves and petioles floccose-pubescent even in age and leaves intermediate 

 between this species and Q. Maryland ica is probably distinct. 



4. Q. Marylandica Muench. BLACK JACK OAK. Leaves short- 

 petioled, wedge-shaped at base, 3-5-lobed at the summit, the lobes 

 toothed, rusty-pubescent beneath : cup 5 // -8 // broad, deep, pubescent, 

 half shorter than the acorn. Common in barrens in the southern part. 

 April-May. 



5. Q. imbricaria Michx. SHINGLE OAK. Leaves lanceolate-oblong, 

 thick, shining above and downy beneath, entire : cup 5 // -7 // broad, acorn 

 subglobose. Common along streams. April-May. 



6. Q. minor (Marsh.) Sarg. POST OAK. Leaves broadly obovate, 

 yellowish-pubescent beneath, pinnatifid into 3-7 broad-toothed lobes : 

 cup 6 // -8 // broad, hemispheric, 1-3J times shorter than the acorn. Com- 

 mon in barrens, especially in the southern part. April-May. 



7. Q. alba L. WHITE OAK. Leaves obovate, nearly glabrous, deeply 

 sinuate-pinnatifid into 3-9, obtuse, often toothed lobes : cup 7 // -10 // broad, 

 depressed hemispherical. 1-3^ times shorter than the acorn. A common 

 forest tree throughout. April-May. 



8. Q. macrocarpa Michx. BUR OAK. Leaves broadly ovate, white- 

 pubescent beneath, irregularly lobed or pinnate : cup 8 // -20 // wide, deep, 

 the scales subulate tipped and forming a mossy fringe, sometimes cover- 

 ing the acorn. Common in rich soil. April-May. 



9. Q. platanoides (Lam.) Sudw. SWAMP WHITE OAK. Leaves ob- 

 ovate, wedge-shaped at base, sinuate-crenate above, white-downy beneath : 

 cup long-peduncled (2-5 times length of petiole), hemispheric: acorn 

 oblong-ovoid. In low grounds around Sheffield and south of Oak Grove. 

 April-May. 



10. Q. acuminata (Michx.) Sarg. CHESTNUT OAK. Leaves oblong- 

 lanceolate, acute or acuminate, sharply toothed : petioles 6 // -12 // long : 

 cup hemispheric, 5 // -8 // broad, peduncled or sessile : acorn ovoid, twice 

 as high as the cup. A tall tree, common throughout. April-May. 



11. Q. prinoides Willd. CHINQUAPIN OAK. A shrub 2-J5 high, 

 very close to the last, but leaves broader and less toothed, on peti- 

 oles "&"-' long. Common in barrens, especially in the southern part. 



April-May. 



FAMILY 32. ULMACEAE Mirbel. 



Trees with alternate, stipulate leaves and clustered or solitary flowers. 

 Calyx of 3-9 sepals. Stamens opposite sep ils. Ovary superior, 1 celled. 

 Ovule one, pendulous. Styles or stigmas two. Fruit a samara or drupe. 



