JUGLANS 



Juglans, Linnaeus, Gen. PI. 291 (1737); Bentham et Hooker, Gen. PL iii. 398 (1880). 



Deciduous 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 monoecious. 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. 



1 Juglans mollis, Engelmann ; J. pyriformis, Liebmann ; andy. mexicana, Watson. 



'''Juglans insularis, Grisebach. Concerning the walnut reputed to occur in Jamaica, y. 'amaicensis, C. DC, cf. Kew. 

 Bull. 1894, p. 371. 



' JtSl""! californua, Watson. 



* Since the above was written, Mr. Dode has published a paper containing descriptions of several new species in Bull. 

 Soc. Dcndr. France, \. 67 (1906) ; but these seem to us to be founded on variable characters, and to be rather forms due to 

 cultivation. 



II 249 H 



