PAGACEAE 29 



3. Leaves acute at base. (European chestnut). C. sativa. 

 Leaves rounded or subcordateat base. (Japanese ).C.crenata. 



4. Petiole villous: nuts several in the bur. C. mollissima. 

 Petiole not villous: nut solitary. (Chinquapin). C. pumila. 



QUERCUS. Oak. 



In our region deciduous trees, or exceptionally shrubs, with 

 yellowish or red-brown hard ring-porous wood with the smal- 

 ler ducts radially arranged, fine medullary rays, with trans- 

 verse bands of wood parenchyma and frequent very heavy in- 

 tervening rays; slender or moderate usually fluted twigs; 

 moderate 5-angled continuous! pith; alternate ratner small 

 half-round somewhat raised leaf-scars with half a dozen scat- 

 tered bundle-traces; minute stipule-scars of filiform persistent 

 stipules; sessile ovoid or conical buds crowded toward the tip, 

 with a considerable number of scales; entire or toothed or 

 mostly pinnately lobed petioled leaves; monoecious small apet- 

 alous flowers, in catkins or axillary; and nut-like fruit with a 

 scaly cup at the base. 



1. Leaves entire. (Willow oaks). 2. 



Leaves coarsely toothed. (Chestnut oaks). 3. 

 Leaves distinctly lobed. 5. 



2. Leaves narrow (under 25mm. wide), glabrous. Q. Phellos. 

 Leaves broad (often 50 mm.) , downy beneath. Q. imbricaria. 



3. Shrub: leaves sharp-toothed, downy beneath. Q. prinoides. 

 Trees: leaves downy beneath. 4. 



4. Leaves with sharp teeth: fruit sessile. Q. Muhlenbergii. 

 Leaves with blunt teeth: fruit long-stalked. Q. bicolor. 



5. Lobes blunt, never bristle-tipped. 6. 

 Lobes acute, ending in bristles. 10. 



6. Leaves pubescent beneath: twigs buff. Q. macrocarpa. 

 Leaves glabrous or nearly so. 7. 



7. Buds conical or pyramidal, gray-pubescent. 8. 



Buds round or ovoid: entirely glabrous. (White o.). Q. alba. 



8. Leaves auricled at base, glabrous. 9. 



Leaves not auricled, midrib sometimes hairy.Q. sessiliflora. 



