calyx (when present) adherent to the incompletely 2- to 4-celled but only 1 -ovulate 

 ovary; ovule orthotropous, erect, at the apex of the incomplete primary partition; 

 fruit similar to a dry drupe, the fibrous-fleshy or woody husk or exocarp (ripened 

 bract and bractlets or involucre and calyx) fused at least until maturity with the 

 crustaceous or bony endocarp or nutshell (ripened carpels), containing a 2- to 

 4-lobed seed. 



A small family of important trees, about 50 species in 7 genera. A number 

 of species in the family produce edible nuts, including the pecans, the Persian or 

 "English" and black walnuts. 



1. Pith of branchlets separating into thin plates; staminate aments separate, 

 sessile, on last year's branchlets, in the axils of the fallen leaves of 

 the previous season; stamens 8 to 40; staminate and pistillate flowers 

 with 4 small sepals; style branches (stigmas) elongate; nut with 

 indehiscent husk and irregularly furrowed shell 1. Juglans 



1. Pith continuous; staminate aments in fascicles of 3, the fascicles subsessile 

 to long-stalked in the axils of bud scales on new growth; stamens 

 3 to 8; staminate and pistillate flowers usually without sepals; 

 stigmas short; husk of fruit splitting or partially splitting into 

 valves, the nutshell smooth or merely reticulate 2. Carya 



1. Juglans L. Walnut. Nogal 



Trees with furrowed scaly bark and durable dark-colored wood; branchlets 

 stout, with laminate pith; leaves pinnate, with numerous serrate leaflets; flowers 

 greenish, produced in spring; staminate aments sessile, separate though often 

 superposed, near the apex of the preceding year's growth; stamens 8 to 40, the 

 floral receptacle adnate to the bract; bractlets 2; sepals usually 4, with some 

 occasionally reduced to minute teeth; filaments free, very short; pistillate flowers 

 solitary or several together in a cluster or short spike on a peduncle at the end of 

 the branch, with a bract and 2 often irregularly toothed bractlets; sepals 4, small; 

 style short, with 2 or rarely 3 elongate style branches that have their inner sur- 

 faces deeply fringed and stigmatic; style branches carinal (above the center of the 

 carpel); fruit with a fibrous-fleshy indehiscent husk (exocarp) and a mostly rough 

 irregularly furrowed nutshell or endocarp. 



About 20 species in both hemispheres. The timber of some species is extremely 

 valuable for cabinet and furniture making. The fruits of most species are also 

 edible. 



1. Fruit 25 mm. or more in diameter; leaflets usually 15 or fewer, with dentate- 

 serrate margins, mostly 15 mm. or more wide 1. J. major. 



1. Fruit rarely more than 20 mm. in diameter; leaflets more than 15, with sub- 

 entire to serrulate margins, rarely more than 15 mm. wide 



2. /. microcarpa. 



1. Juglans major (Torr.) Heller. Arizona walnut, nogal silvestre. 



Tree to about 15 m. high, with trunk to 12 dm. in diameter, the bark deeply 

 furrowed and ridged on older trees; branches widely spreading to form a rounded 

 crown; twigs reddish-brown, densely hairy when young, with age becoming ashy- 

 gray; leaves to 35 cm. long; leaflets usually 9 to 13, rarely more, essentially 

 sessile, lanceolate, acuminate at apex, more or less falcate, to 1 dm. long and 

 35 mm. wide below the middle, coarsely dentate-serrate on margins, thin, yellowish- 

 green, scurfy-hairy when young, essentially hairless with age; fruit spherical, 

 25-35 mm. in diameter; husk brown, thin, densely hairy; nut with a thick hard 

 shell and a small edible kernel. 



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