JUGLANS
- Juglans, Linnæus, Gen. Pl. 291 (1737); Bentham et Hooker, Gen. Pl. iii. 398 (1880).
Decidious 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[1] confined to Mexico, one[2] a native of the Antilles, and the Californian walnut[3] have not yet been introduced, and will not be dealt with in the following account.[4]
Plate 73 illustrates the leaves, branchlets, and leaf-scars of the species in cultivation.
- ↑ Juglans mollis, Engelmann; J. pyriformis, Liebmann; and J. mexicana, Watson.
- ↑ Juglans insularis, Grisebach. Concerning the walnut reputed to occur in Jamaica, J. jamaicensis, C. DC., cf. Kew. Bull. 1894, p. 371.
- ↑ Juglans californica, Watson.
- ↑ Since the above was written, Mr. Dode has published a paper containing descriptions of several new species in Bull. Soc. Dendr. France, i. 67 (1906); but these seem to us to be founded on variable characters, and to be rather forms due to cultivation.
