JUGLANDACE^E 177 



Leaflets 7-9; nut cylindric or slightly compressed. 3. C. cordiformis (A, C). 



Leaflets 7-13; nut compressed, usually conspicuously wrinkled. 4. C. aquatica (C). 

 Shell of the ellipsoidal cylindric nut thick and hard; lobes of the sweet seed deeply 2-lobed; 

 leaflets 7-9, occasionally 5, rarely slightly falcate; aments of staminate flowers long- 

 pedunculate at the base of branches of the year. ' 5. C. myristicaefonnis (C). 

 Bud-scales imbricated, the inner becoming much enlarged and often highly colored; aments 

 of staminate flowers on peduncles from the base of branches of the year, rarely from the 

 axils of leaves; fruit usually without wings; partitions of the nut thick without cavities 

 filled with astringent powder; seed sweet, its lobes deeply 2-lobed. 

 Branchlets usually stout (slender in 7); involucre \'-%' in thickness, opening freely 

 to the base. 



Bark on old trunks separating into long, broad, loosely attached plates; nuts pale. 

 Branchlets light red-brown; shell of the nut thin. 



Leaflets 5 or rarely 7, obovate to ovate, acute or acuminate; nut much compressed, 



often long-pointed at apex; branchlets glabrous or pubescent. 6. C. ovata (A, C). 



Leaflets 5, lanceolate, acuminate; nut little compressed, acute at apex; branchlets 



slender, glabrous. 7. C. carolinae-septentrionalis (C). 



Branchlets pale orange color, pubescent; leaflets usually 7-9; shell of the nut thick. 



8. C. laciniosa (A, C). 



Bark not scaly, on old trunks dark, deeply ridged; leaflets 7-9, often subcoriaceous, 



pubescent below; nut reddish brown, often long-pointed, thick shelled; branchlets 



pubescent. 9. C. alba (A, C). 



Branchlets slender; leaves 5-7-foliolate; involucre of the fruit tardily dehiscent to the 



middle, indehiscent or opening freely to the base; shell of the nut thick, bark close, 



(sometimes scaly in 13). 



Branchlets and leaves not covered when they first appear with rusty brown pubescence. 

 Involucre of the fruit 3-5.5 mm. in thickness, opening freely to the base, leaves 



usually 7-foliolate; winter-buds pubescent. 



Leaflets hoary tomentose below in early spring, slightly pubescent at maturity; 

 petioles and rachis glabrous; fruit broad-obovoid; branchlets glabrous. 



10. C. leiodermis (C). 



Leaflets covered in early spring with silvery scales, pale and pubescent below 

 during the season; petioles and rachis more or less thickly covered with fasci- 

 cled hairs; fruit ellipsoidal to obovoid or globose; branchlets glabrous or 

 slightly pubescent. 11. C. pallida (A, C). 



Involucre of the fruit 1-3 mm. in thickness; winter-buds glabrous or puberulous. 

 Leaves 5, rarely 7-foliolate, glabrous or rarely slightly pubescent; fruit obovoid, 

 often narrowed below into a stipitate base, the involucre indehiscent or tardily 

 dehiscent. 12. C. glabra (A, C). 



Leaves generally 7-foliolate, glabrous or rarely pubescent; fruit ellipsoidal, sub- 

 globose or obovoid, the involucre opening freely to the base; bark often more 

 or less scaly. 13. C. ovalis (A, C). 



Branchlets and leaves densely covered when they first appear with rusty brown pubes- 

 cence; leaflets usually 5-7; winter-buds rusty pubescent. 



Fruit obovoid; the involucre 2-3 mm. in thickness; peduncles of the aments of 

 staminate flowers often from the axils of leaves; branchlets soon becoming 

 glabrous. 14. C. floridana (C). 



Fruit subglobose to broadly obovoid, ellipsoidal or pyriform, the involucre on the 

 different varieties 2-13 mm. in thickness; branchlets pubescent through their 

 first season. 15. C. Buckley! (A, C). 



1. Carya pecan Asch. & Gr. Pecan. 

 Leaves 12'-20' long, with slender glabrous or pubescent petioles, and 9-17 lanceolate to 

 rag-lanceolate more or less falcate long-pointed coarsely often doubly serrate leaflets 



