Carya Juglandaceae 367 



1882. CARYA Nutt. Hickory 



The specimens representing a single species of Carya often vary greatly 

 in respect to the bark of both trunks and branches, size and pubescence of 

 branchlets, number and size of the leaflets, and size and shape of the nuts. 

 No attempt has been made to describe all of the extreme forms. Measure- 

 ments refer to dried specimens. 



Bud scales 4 or 6, valvate; leaflets generally curved backward (falcate). 

 Nuts generally elongate, nearly terete; husk thin, splitting to the base; kernel 



sweet; leaflets 9, 11, 13, 15 or 17, generally about 13 1. Carya Pecan. 



Nuts generally as broad as long, compressed, irregularly angled and reticulate; 

 kernel bitter. 

 Winter buds dark reddish brown; leaflets 7, 9, 11 or 13; husk tardily splitting 



to about the middle. (See excluded species no. 169, p. 1039.) C. aquatica. 



Winter buds bright yellow, glandular; leaflets 5, 7 or 9 (11) ; husk usually splitting 



to about the middle 2. C. cordiformis. 



Bud scales 6 or more, imbricated (not in pairs); leaflets not curved backward. 



A. Branchlets usually stout; terminal buds large, 10-27 mm long; the year's growth 

 usually more or less pubescent; dry husks of fruit (4) 5-10 mm thick; nuts 

 usually strongly angled. 

 Prevailing number of leaflets 5 (none of the leaves with more than 5, coppice 



shoots might have more) 3. C. ovata. 



Prevailing number of leaflets more than 5. 



Trees of low ground; bark of young trees tight and light, that of older trees 

 scaly, separating into long, thin plates (see exception in text); leaf stalks 

 of leaves of the previous season usually persisting until spring (this char- 

 acter peculiar to this species); branchlets at first pubescent, generally 

 becoming glabrous or nearly so at maturity, light brown; nuts usually 

 large, compressed, generally angled, 3-6 cm long, wedge-shaped at the 



base; kernel sweet and not at all astringent 4. C. laciniosa. 



Trees usually of high ground; bark of young trees tight and dark, that of older 

 trees tight and usually deeply furrowed, the thick ridges generally broken 

 into short lengths which on very old trees sometimes loosen at the base; 

 leaf stalks of the leaves of the previous season not persisting; pubescence 

 of leaf stalks usually longer and denser than that of the preceding species, 

 and persisting longer, often of a rusty color; branchlets more or less pubes- 

 cent until maturity, reddish brown; nuts usually about half as large as the 

 preceding and usually with a rounded base; kernel very mildly astringent.. . 



5. C. tomentosa. 



A. Branchlets usually slender; terminal buds small, 5-12 mm long; the year's 

 growth usually glabrous, rarely pubescent; dry husk 1-4.5 mm thick. 

 B. Branchlets and leaves not covered with a rusty brown pubescence when they 

 first appear; dry husk 1-3 mm thick at thinnest point, rarely thicker. 

 Involucre of fruit 1-3 mm thick; winter buds glabrous or puberulous. 



Prevailing number of leaflets 5, rarely 7; bark of trunk and branches tight; 

 fruit generally smooth and usually tapering at the base to a short stem 

 (figlike); husk not opening or splitting only above the middle; nut smooth, 

 the shell thick, about 1.5 mm thick at the thinnest point; kernel sweet, 



mildly astringent 6. C. glabra. 



Prevailing number of leaflets 7, rarely 5; bark of trunk and branches usually 

 somewhat scaly a few feet above the ground, sometimes scarcely at all 

 scaly; fruit granular, the sutures winged, rarely tapering at the base to a 

 short stem (figlike); husk usually splitting to the base; nut angled or 



