70 FAGACEAE 



1. C. roBtrata Ait. Beaked Hazel Nut. Like the next, but 

 smoother : involuoral 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-shrnb throughout. March-April. 



Family 31. FAGACEAE Drnde. 

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

 tended by an involucre which in truit 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 3-51obed 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. maerocarpa. 



Leaves crenate or dentate but not lobed. 

 Leaves whitish-downy beneath. 9. Q. platanoide.^. 



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, 3'-8' 

 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, W-Yi," broad : 

 acorn ovoid, V 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. 



