70 FAGACEAE 



1. C. rostrata Ait. BEAKED HAZEL NUT. Like the next, but 

 smoother : involucral bracts united and prolonged into a beak twice as 

 long as the nut. Thickets in the northeastern part. April. 



2. C. Americana Walt. HAZEL NUT. 3-10 high, with ovate, 

 pointed, serrulate leaves, downy beneath : involucral bracts jagged and 

 incised at the apex, hardly united, not prolonged into a beak. A com- 

 mon under-shrub throughout. March-April. 



FAMILY 31. FAGACEAE Drude. 



Trees or shrubs like the last, but pistillate flowers solitary or few, sub- 

 tended by an involucre which in fruit forms a cup. Staminate flowers 

 with a 4-7-lobed calyx, and 4-20 stamens. Ovary 3-7-celled, with 1-2 

 ovules in each, but only one ripening, in fruit forming a 1-seeded nut 

 with a thick, bony husk. 



1. QUERCUS L. 



Trees with varied leaves. Staminate flowers in aments. Calyx of 

 staminate flowers usually 6-lobed. Ovary 3-celled, 6-ovuled. Fruit con- 

 sisting of an acorn, subtended by a scaly-covered, hard involucre (cup). 

 Several interesting hydrids occur. 



Leaves lobed, the lobes bristle-tipped. 

 Leaves pinnately lobed. 



Cups of acorns saucer- shaped. 



Cups 8 // -12 // broad. 1. Q. rubra. 



Cups 5"-8" broad. 2. Q. Texana. 



Cups of acorns hemispheric. 3. Q. velutina. 



Leaves 3-5 lobed above the middle. 4. Q. Marylandica. 



Leaves entire. 5. Q. imbricaria. 



Leaves lobed but not bristle-tipped. 



Leaves brown-tomentulose beneath. 6. Q. minor. 



Leaves not brown-tomentulose beneath. 



Old leaves glabrous beneath. 7. Q. alba. 



Old leaves pubescent beneath. 8. Q. macrocarpa. 



Leaves crenate or dentate but not lobed. 



Leaves whitish-downy beneath. 9. Q. platanoides. 



Leaves smoothish beneath. 



Tree: leaves oblong or lanceolate. 10. Q. acuminata. 



Shrub: leaves obovate. 11. Q. prinoides. 



1. Q. rubra L. RED OAK. Leaves oval to obovate in outline, S'-S 7 

 long, 2 / -6 / wide, slender-petioled, sinuate-pinnatifid to deeply pin- 

 natifid, green and glabrous above when old, pubescent in axils of veins 

 beneath : cup saucer-shaped, much broader than high, 8 // -12 // broad : 

 acorn ovoid, l x long, 2-4 times the length of the cup. A common forest 

 tree. April-May. 



2. Q. Texana Buckley. TEXAS RED OAK. Like the last but leaves 

 glabrous, pinnatifid and bristle-tipped, smaller : cup 5 // -8 // broad : acorn 

 less than V long, 2-3 times length of the glabrous cup. Along streams 

 northeast of Independence and southeast of Grain Valley. Rare. April- 

 May. 



