176 TREES OF NORTH AMERICA 



Distribution. Coast region of central California; banks of the lower Sacramento River; 

 along streams near the western base of Mt. Diabolo, and on eastern slope of the Napa 

 Range near Atlas Peak east of Napa Valley; near Loyalton in the Sierra Valley. 



Often cultivated in California as a shade tree and as stock on which to graft varieties 

 of Juglans regia L., and rarely in the eastern states and in Europe. In California, a hybrid 

 known as " Paradox " between J. Hindsii and J. regia has been artificially produced. 



2. CARYA NUTT. Hickory. 

 Hicoria Rafn. 



Trees, with smooth gray bark becoming on old trunks rough or scaly, strong hard tough 

 brown heartwood, pale sapwood and tough terete flexible branchlets, solid pith, buds covered 

 with few valvate or with numerous imbricated scales, the axillary buds much smaller than 

 the terminal. Leaves often glandular-dotted, their petioles sometimes persistent on the 

 branches during the winter, and in falling leaving large elevated oblong or semiorbicular 

 more or less 3-lobed emarginate leaf-scars displaying small marginal clusters and central 

 radiating lines of dark fibre-vascular bundle-scars; leaflets involute in the bud, ovate or 

 obovate, usually acuminate, thick and firm, serrate, mostly unequal at base, with veins 

 forked and running to the margins; turning clear bright yellow in the autumn. Aments of 

 the staminate flowers ternate, slender, solitary or fascicled in the axils of leaves of the 

 previous or rarely of the current year, or at the base of branches of the year from the 

 inner scales of the terminal bud, the lateral branches in the axils of lanceolate acute per- 

 sistent bracts; calyx usually 2 rarely 3-lobed, its bract free nearly to the base and usually 

 much longer than the ovate rounded or acuminate calyx-lobes; stamens 3-10, in 2 or 3 

 series, their anthers ovate-oblong, emarginate or divided at apex, yellow or red, pilose or 

 hirsute, as long or longer than their slender connectives; pistillate flowers sessile, in 2-10- 

 flowered spikes, with a perianth-like involucre, slightly 4-ridged, unequally 4-lobed at apex, 

 villose and covered on the outer surface with yellow scales more or less persistent on the 

 fruit, the bract much longer than the bractlets and the single calyx-lobe; stigmas short, 

 papillose-stigmatic. Fruit ovoid, globose or pyriform, with a thin or thick husk becoming hard 

 and woody at maturity, 4-valved, the sutures alternate with those of the nut, sometimes 

 more or less broadly winged, splitting to the base or to the middle; nut oblong, obovoid 

 or subglobose, acute, acuminate, or rounded at apex, tipped by the hardened remnants of 

 the style, narrowed and usually rounded at base, cylinclric, or compressed contrary to the 

 valves, the shell thin and brittle or thick, hard, and bony, smooth or variously rugose or 

 ridged on the outer surface, 4-celled at base, 2-celled at apex. Seed compressed, variously 

 grooved on the back of the flat or concave lobes, sweet or bitter. 



Carya is confined to the temperate region of eastern North America from the valley 

 of the St. Lawrence River to the highlands of Mexico, and to southern China where one 

 species occurs. Of the seventeen species, fifteen inhabit the territory of the United States. 



The generic name is from Kapva an ancient name of the Walnut. 



CONSPECTUS OF THE SPECIES OF THE UNITED STATES. 



Bud-scales valvate, the inner strap-shaped and only occasionally slightly accrescent; fruit 

 more or less broadly winged at the sutures; the thin partitions of the nut containing 

 cavities filled with dark astringent powder (absent in 3 and 5). 

 Shell of the nut thin and brittle; leaflets more or less falcate. 



Aments of staminate flowers nearly sessile, usually on branches of the previous year: 



lobes of the seed entire or slightly notched at apex. 



Leaflets 9-17; nut ovoid-oblong, cylindric; seed sweet. 1. C. pecan (A, C). 



Leaflets 7-13; nut oblong, compressed; seed bitter. 2. C. texana (C). 



Aments of staminate flowers pedunculate, on branches of the year or of the previous 

 year; lobes of the bitter seed deeply 2-lobed. 



