22 JUGLANDACEAE 



scars with 3 crescent-shaped or compound bundle-traces; no 

 stipule-scars; superposed buds with several, sometimes lobed, 

 scales; large odd-pinnate leaves; small monoecious apetalous 

 flowers in catkins; and large nuts with hard shell enclosed 

 by an indehiscent fleshy pericarp; pith finally chambered. 



1. Leaf -scars 1 with a downy cross-line at top. 2. 

 Leaf-scars without a downy ridge at top, notched. 3. 



2. Twigs moderate: leaf-scars not notched. J. cinerea. 

 Twigs stout: leaf-scars notched. (Japanese). J. Sieboldiana. 



3. End buds elongated: nuts small. J. rupestris. 

 End buds scarcely longer than thick; nuts large. 4. 



4. Buds ashen-pubescent. (Black walnut). J. nigra. 

 Buds glabrate. (European walnut). , J. regia. 



PTEROCARYA. 



Deciduous trees with pale wood with rather sparse and 

 small diffused ducts and fine medullary rays with wood-paren- 

 chyma cross-lines; moderately stout terete twigs; somewhat 

 5-sided brownish chambered pith; alternate somewhat raised 

 obtusely triangular or 3-lobed leaf-scars with 3 compound 

 bundle-traces; no stipule-scars; scaly and solitary, or naked 

 and superposed, buds the uppermost sometimes long-stalked; 

 large odd-pinnate leaves with toothed leaflets; inconspicuous 

 monoecious apetalous flowers in catkins; and variously winged 

 nut-like fruits. 



1. Buds naked, superposed. 2. 



Lateral buds scaly, solitary. P. rhoifolia. 



2. Rachis of leaves winged. P. stenoptera. 

 Rachis not winged. P. fraxinifolia* 



CARYA. Hickory. 



Rather large deciduous trees with mostly rough bark; 

 hard finally often reddish or brownish wood with the ducts 

 crowded and large in the spring growth but usually smaller or 

 sparser later in the season, and very fine medullary rays con- 

 nected by equally heavy cross-lines of wood parenchyma; 

 mostly stout terete twigs; rather large roundish essentially 



