1. JUGLANS L. Walnut.
Trees, with furrowed scaly bark, durable dark-colored wood, stout branchlets, laminate pith, terminal buds with 2 pairs of opposite more or less open scales often obscurely pinnate at apex, those of the inner pair more or less leaf-like, and obtuse slightly flattened axillary buds formed before midsummer and covered with 4 ovate rounded scales, closed or open during winter. Leaves with numerous leaflets, and terete petioles leaving in falling large conspicuous elevated obcordate 3-lobed leaf-scars displaying 3 equidistant U-shaped clusters of dark fibro-vascular bundle-scars; leaflets conduplicate in the bud, ovate, acute or acuminate, mostly unequal at base, with veins arcuate and united near the margins. Aments of the staminate flowers many-flowered, elongated, solitary or in pairs from lower axillary buds of upper nodes, appearing from between persistent bud-scales in the autumn and remaining during the winter as short cones covered by the closely imbricated bracts of the flowers; calyx 3—6-lobed, its bract free only at the apex; stamens 8—40, in 2 or several ranks, their anthers surmounted by a conspicuous dilated truncate or lobed connective; pistillate flowers in few-flowered spikes, their involucre villose, free only at the apex and variously cut into a laciniate border (corolla?) shorter than the erect calyx-lobes; ovary rarely of 3 carpels; stigmas club-shaped, elongated, fimbriately plumose. Fruit ovoid, globose or pyriform, round or obscurely 4-angled, with a fleshy indehiscent glabrate or hirsute husk; nut ovoid or globose, more or less flattened, hard, thick-walled, longitudinally and irregularly rugose, the valves alternate with the cotyledons, and more or less ribbed along the dorsal sutures and in some species also on the marginal sutures. Seed more or less compressed, gradually narrowed or broad and deeply lobed at base, with conspicuous dark veins radiating from the apex and from the minute basal hilum.
Juglans is confined to temperate North America, the West Indies, South America from Venezuela to Peru, western and northern China, Korea, Manchuria, Japan, and Formosa. Eleven species are known. Of exotic species Juglans regia L., an inhabitant probably originally of China, is cultivated in the middle Atlantic and southern states and largely in California for its edible nuts, which are an important article of commerce. The wood of several species is valued for the interior finish of houses and for furniture.
Juglans, from Jupiter and glands, is the classical name of the Walnut-tree.
CONSPECTUS OF THE NORTH AMERICAN SPECIES.
Fruit racemose; nut 4-ribbed at the sutures with smaller intermediate ribs, 2-celled at the base; heartwood light brown; leaflets 11—17, oblong-lanceolate.1. [J. cinerea] (A, C). Fruit usually solitary or in pairs; nut without sutural ribs, 4-celled at the base; heartwood dark brown. Nuts prominently and irregularly ridged with often interrupted ridges; leaflets 15—23, ovate-lanceolate.2. [J. nigra] (A, C). Nuts more or less deeply longitudinally grooved. Nuts up to 1½′ in diameter; leaflets 9—13, rarely 19, oblong-lanceolate to ovate, acuminate, coarsely serrate.3. [J. major] (F, H). Nuts not more than ¾′ in diameter. Leaflets 17—23, narrow-lanceolate, long-pointed.4. [J. rupestris] (C). Leaflets 11—15 or rarely 19, oblong-lanceolate, acute or acuminate, the lower often rounded at the apex.5. [J. californica] (G). Nuts obscurely or not at all grooved, up to 2′ in diameter; leaflets 15—19, ovate-lanceolate to lanceolate, long-pointed.6. [J. Hindsii] (G).
1. [Juglans cinerea] L. Butternut.
Leaves 15′—30′ long, with stout pubescent petioles, and 11—17 oblong-lanceolate acute or acuminate leaflets 2′—3′ long, 1½′—2′ wide, finely serrate except at the unequal rounded base, glandular and sticky as they unfold, at maturity thin, yellow-green and rugose above, pale and soft-pubescent below; turning yellow or brown and falling early in the autumn. Flowers: staminate in thick aments 3′—5′ long; calyx usually 6-lobed, light yellow-green, puberulous on the outer surface, ¼′ long, its bract rusty-pubescent, acute at apex; stamens 8—12, with nearly sessile dark brown anthers and slightly lobed connectives; pistillate in 6—8-flowered spikes, constricted above the middle, about ⅓′ long, its bract and bractlets coated with sticky white or pink glandular hairs and rather shorter than the linear-lanceolate calyx-lobes; stigmas bright red, ½′ long. Fruit in 3—5 fruited drooping clusters, obscurely 2 or rarely 4-ridged, ovoid-oblong, coated with rusty clammy matted hairs, 1½′—2½′ long with a thick husk; nut ovoid, abruptly contracted and acuminate at apex, with 4 prominent and 4 narrow less conspicuous ribs, light brown, deeply sculptured between the ribs into thin broad irregular longitudinal plates, 2-celled at the base and 1-celled above the middle; seed sweet, very oily, soon becoming rancid.
A tree, occasionally 100° high, with a tall straight trunk 2°—3° in diameter, and sometimes free of branches for half its height; more frequently divided 20° or 30° above the ground into many stout limbs spreading horizontally and forming a broad low symmetrical round-topped head, and dark orange-brown or bright green rather lustrous branchlets coated at first with rufous pubescence, covered more or less thickly with pale lenticels, gradually becoming puberulous, brown tinged with red or orange in their second year and marked by light gray leaf-scars with large black fibro-vascular bundle-scars and elevated bands of pale tomentum separating them from the lowest axillary bud. Winter-buds: terminal ½′—⅔′ long, ¼′ wide, flattened and obliquely truncate at apex, their outer scales coated with short pale pubescence; axillary buds ovoid, flattened, rounded at apex, ⅛′ long, covered with rusty brown or pale pubescence. Bark of young stems and of the branches smooth and light gray, becoming on old trees ¾′—1′ thick, light brown, deeply divided into broad ridges separating on the surface into small appressed plate-like scales. Wood light, soft, not strong, coarse-grained, light brown, turning darker with exposure, with thin light-colored sapwood composed of 5 or 6 layers of annual growth; largely employed in the interior finish of houses, and for furniture. The inner bark possesses mild cathartic properties. Sugar is made from the sap, and the green husks of the fruit are used to dye cloth yellow or orange color.