18 



JUGLANDACEAE. 



Carya. Hickory. 

 (Family Juglandaceae). 



Trees: deciduous. Twigs mod- 

 erate, terete: pith moderate, an- 

 gled, often brown, continuous or 

 broken at the nodes. Buds rather 

 large, sometimes stalked or super- 

 posed, the terminal larger, ovoid 

 or oblong, apparently naked or 

 with 1 or several exposed scales. 

 Leaf-scars alternate, shield-shaped 

 or 3-lobed, large, low: bundle- 

 traces numerous in 3 or 4 more 

 or less definite groups: stipule- 

 scars lacking. 



1. Bud-scales in pairs. 2. 

 Bud-scales not opposite. 3. 



2. Yellow-glandular: fruit bitter. 



(1). C. cordiformis. 



Scarcely glandular: fruit sweet. 



(Pecan). (2). C. Pecan. 



3. Terminal bud large (usually over- 10 mm.). (Hickories). 4. 

 Terminal bud small (scarcely 10 mm.). (Pignuts). 7. 



4. Outer bud-scales falling early. (Mockernut). C. alba. 

 Outer scales persistent, pointed. (Shagbarks). 5. 



5. Twigs buff or orange: fruit very large. C. laciniosa. 

 Twigs gray or red-brown: fruit smaller. 6. 



6. Twigs glabrate. (Shagbark). (3). C. ovata. 

 Twigs hairy. (Hairy Shagbark). C. ovata hirsuta. 



7. Bark very rough, broken into squares. C. villosa. 

 Bark rather smooth or flaking. 8. 



8. Husk of fruit not splitting far. (Eastern). C. glabra. 

 Husk splitting nearly to base. (Western pignut). C. ovalis. 



