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trees with furrowed bark. Twigs with chambered pith. Buds scaly, the lateral buds often extra-axillary or accompanied by superposed accessory buds. Leaf-scars large with three groups of bundle-traces. Leaves large, alternate, compound, imparipinnate; leaflets opposite, entire or serrate. Stipules absent.

Flowers monœcious. Male flowers numerous in pendulous catkins, which arise singly or in pairs above the leaf-scars of the preceding year's shoot, appearing in autumn and then visible as short cones covered by imbricated scales. Stamens eight to forty, in several series on the axis of a scale, which is five- to seven-lobed, the lobes representing a bract, two bracteoles and two to four perianth-lobes. Connective of the anthers clavate or dilated. Pistillate flowers few, in an erect spike terminating the current year's shoot; each flower with a three- to five-lobed or toothed involucre, composed of a bract and two bracteoles, adnate to the ovary. Inside the involucre is an epigynous and adherent four-lobed or toothed perianth. Ovary one-celled with one basal straight ovule. Style divided into two linear or lanceolate recurved spreading fimbriated plumose stigmas.

Fruit a large ovoid, globose, or pear-shaped drupe, with a fleshy, irregularly splitting husk, formed by the accrescent involucre and perianth. Nut ovoid or globose, thick-walled, longitudinally and irregularly wrinkled, two- to four-celled at the base, indehiscent or separating at last into two valves. Seed two- to four-lobed at the base, with fleshy cotyledons, which remain within the shell in germination.

About thirteen species of Juglans have been described; and there are two or three unnamed and little-known species in tropical South America. Of the described species three confined to Mexico, one a native of the Antilles, and the Californian walnut have not yet been introduced, and will not be dealt with in the following account.

Plate 73 illustrates the leaves, branchlets, and leaf-scars of the species in cultivation.

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