KEY TO THE SPECIES OF HICKORIES 



1. Bud naked or with 4-6 valvate scales; leaflets 7-17, usually lanceolate, 

 often falcate, about of same size; fruit husk winged. Pecans 

 2. Nuts about twice as long as broad, sweet, thin-shelled; buds 

 brown, covered with yellow hairs; leaflets 9-17; bark thick, fur- 

 rowed; Illinois to Alabama and Texas C. illinoensis. Pecan, p. 145. 

 2. Nuts about as long as broad; leaflets 7-13; bark scaly. 



3. Leaflets 7-9 (rarely 5-11), ovate-lanceolate to obovate; buds 

 brown, hairy; nut sweet, with thick, hard shell; South Carolina 



to Arkansas and south 



C. myristicaeformis, Nutmeg Hickory, p. 145. 



3. Leaflets lanceolate to ovate-lanceolate; nut bitter. 



4. Leaflets 7-13 (usually 9-11); buds red-brown; Virginia to 



Illinois and south C. aquatica. Water Hickory, p. 145. 



4, Leaflets 7-9 (usually 7); buds bright yellow; Quebec to 



Minnesota and south 



C. cordiformis, Bitternut Hickory, p. 145. 



1. Bud with more than 6 overlapping scales; leaflets 3-9, the uppermost 

 largest; husk usually without wings; nut thick-shelled, sweet (except 

 in pignut hickory). True Hickories 



5. Terminal buds H-1 M inches long; twigs thick; fruit 1-2 H inches 

 long. 



6. Bark on old trunks shaggy with loose plates; fruit husk }4-}4 

 inch thick; upper 3 leaflets conspicuously larger than others; 

 twigs and petioles glabrous to hairy. 



7. Leaflets usually 7 (rarely 5-9), hairy below; twigs pale 

 orange, hairy; shell very thick; New York to Kansas and 



south C. laciniosa, Shellbark Hickory, p. 141. 



7. Leaflets usually 5 (rarely 7), glabrous or slightly hairy 

 below; twigs red-brown, usually glabrous; Quebec to Minne- 

 sota and south C. ovata, Shagbark Hickory, p. 141. 



6. Bark on old trunks close; fruit husk K-M inch thick; leaflets 

 5-9, of about same size; twigs and petioles often woolly; Massa- 

 chusetts to Nebraska and south 



C. tomentosa, Mockernut Hickory, p. 143. 



5. Terminal buds M-M inch long; twigs moderately thick to slender; 

 fruit M-1 H inches long; Bark on old trunks close; fruit husk 

 1/12-1/4 inch thick. 

 8. Winter buds and leaves glabrous or pale hairy. 



9. Buds, leaves, and petioles essentially glabrous; husk of fruit 

 very thin (1/12-1/8 inch); leaflets 5 (rarely 3-7); nut bitter, 

 shell ridged from base to apex; husk obovoid; Maine to 

 Minnesota and south . . C. glabra, Pignut Hickory, p. 143. 

 9. Winter buds and leaves with silvery or pale hairs; husk of 

 fruit yg-H inch thick; leaflets 7 (rarely 5-9). 

 10. Leaves covered with silvery scales in spring; petiole 

 and rachis hairy; fruit ellipsoidal to globose; Virginia 



to Tennessee and south 



C. pallida. Sand Hickory, p. 143. 



10. Leaves woolly in spring; petioles glabrous; fruit obovoid; 



Arkansas to Texas and Mississippi 



C. leiodermis. Swamp Hickory, p. 143. 



8. Buds, twigs, and leaves red-hairy; leaflets 5-7. 



11. Fruit obovoid; Florida C. floridana. Scrub Hickory, p. 143. 



11. Fruit subglobose, obovoid, or pyriform; Indiana to Kansas, 



Texas, and Louisiana. . . C. texana. Black Hickory, p. 143. 



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