Leaflets 9-17, generally about 13; nut elongated, circular in cross-section; kernel sweet 1 C. illinoensis. Leaflets 5-9, generally 5-7; nut about as broad as long, compressed in cross-section; kernel bitter 2 C. cordiformis. Bud scales more than 6, imbricated (not in pairs); leaflets not curved backward. Branchlets usually stout; terminal buds large, 7-25 mm. long; the year's growth usually more or less hairy; dry husks 4-10 mm. thick. Prevailing number of leaflets 5 3 C. ovata. Prevailing number of leaflets more than 5. Trees of low ground; bark of young trees tight and light, of older trees scaly, separating into long thin plates; branchlets usually light orange color; nuts usually large, compressed, 3-6 cm. long, pointed at base 4 C. laciniosa. Trees of high ground; bark of young trees tight and dark, of older trees tight and deeply furrowed, the thick ridges broken into short lengths which on very old trees loosen at the base; branchlets reddish-brown; nuts usually about half as large as the preceding and usually with a rounded base 5 C. alba. Branchlets usually slender; terminal buds small, 5-12 mm. long; the year's growth usually glabrous, rarely hairy; dried husk 1-2.5 mm. thick. Branchlets and leaves not covered when they first appear with rusty-brown pubescence. Prevailing number of leaflets 5; fruit usually smooth and tapering at base to a short stem (fig-like); shell of nut thick, kernel sweet and astringent 6 C. glabra. Prevailing number of leaflets generally 7; fruit usually granular, rarely tapering at the base to a short stem (fig-like); shell of nut thin, kernel sweet without astringency 7 C. ovalis. Branchlets and leaves densely covered when they first appear with rusty-brown pubescence 8 C. Buckleyi.