OAK FAMILY. 301 



J. nigra. BLACK W. Large tree, commoner W. & R. : stalks and shoote 

 not clammy, minutely downy ; leaflets smoothish, ovate-lanceolate, serrate ; 

 fruit spherical. 



* * Planted from the Old Worli! : husk friable, separating when dry from the 



roundish and smoothish thin-shelled nut. 



3. l'6gia, ENGLISH WALNTT, so called, but native of Asia: leaflets oval, 

 entire, smoothish; fruit ripens sparingly in Middle States. 



2. CARYA, HICKORY. (Greek name of the Walnut, applied to these 



North American trees.) FI. in rather late spring : nuts fall in autumn. 



1. Sterile catkins in a sessile cluster: leaflets 13-15, short-stalked: nut edible. 



C. olivseformis, PECAN-NUT. Along rivers, from Illinois S. ; leaflets 

 oblong-lanceolate, taper-pointed; nut cylindrical-oblong, olive-shaped, the seed 

 delicious. 



2. Sterile catkins 3 or more together on a common peduncle: leaflets sessile or 

 nearly so, of 5-9 or rarely 11-13 leaflets : nut globular or short-oval. 



* Xuts sweet-tasted and edible (the hickory-mils of the market) ; the husk splitting 



into 4 thick and hard valves : buds large, of about 10 w </.',.<;. 



C. alba, SHELL-BARK or SHAG-BARK H. Commonest E. : bark of old 



trunks very shaggy, separating in rough strips ; inner bud-scales becoming very 

 laruo and conspicuous on the young shoot ; leaflets 5, the 3 upper much larger 

 and lance-obovate ; nut white. 



C. sulcata, WESTERN SHELL-BARK H. From Penn. W. & S. : differs 

 from the foregoing in lighter-colored heart-wood, 7 -9 leaflets IIKUV downy be- 

 neath, fruit with very thick husk 4-ribbed above the middle, and larger yellow- 

 ish or dull-white nut (sometimes 2' long) mostly with a point at both ends. 



C. tomentosa, MOCKER-NUT or WHITE-HEART H. Common Iv S. : 

 bark rough, but not splitting off in strips ; shoots and lower surface of the 

 leaves woolly-downy when young; leaflets 7-9, lance-obovatc, or the lower 

 lance-oblong ; fruit with very thick hard husk, and globular nut (not flatfish on 

 the sides) brownish, very thick-shelled, hardly fit to eat. 



* * Nuts bitter, in a rather thin and friable husk, which splits onfi/ at the top, or 



tardily to near the base : bark on the trunk close : bud-scales falling early. 



C. porcina, BROWN H. or PIG-NUT. Common N. : bark of trunk 

 rough; bud-scales about 10, small; schools and leaves nearly smooth; leaflets 

 5-7, obovate-lanccolate ; fruit pear-shaped; nut oblong or oval, hard-shelled, 

 seed at first sweet, then bitterish. 



C. amara, BITTER-NUT. Moist or low grounds : bark of trunk smooth and 

 very close; yellowish bud-scales about 6 ; shoots and leaves pubi>eent when 

 young; leaflets 7- 11, lanceolate or lance-oblong; fruit and white thin-shelled 

 and tender nut globular ; seed at first sweet, then very bitter. 



C. aquatica, WATER H. River-swamps S. ' Small tree, with rou-h 

 bark; bud-scales as in the last; leaflets 9-13, lanceolate, smooth; nut thin- 

 shelled, 4-angular, flattish ; seed very bitter. 



106. CUPULIFER.SI, OAK FAMILY. 



Trees or shrubs, with alternate and simple straight-veined leaver 

 very deciduous stipules, and monoecious flowers ; the sterile in 

 slender catkins (except in the Beech) ; the fertile solitary, clustered, 

 or sometimes spiked, and furnished with an involucre which forms 

 a cup or covering to the 1-celled 1 -seeded nut. This nut comes 

 from an ovary with 2 or more cells having one or two ovules hang- 

 ing from the summit of each ; but all .-xc.-pt one cell and one 

 ovule are abortive. There is a calyx adhering to the ovary, as is 

 shown by the minute teeth crowning its summit. Seed filled by 

 the embryo, which has thick and fleshy cotyledons. 



