Western Hemisphere and Eurasia.
Genera 7, species 59 (2 genera, 17 species in the flora).
The fruit in Juglandaceae superficially resembles a drupe, with a hard "stone" surrounded by a soft, often fleshy husk. The husk, however, is not part of the fruit wall (it develops from the involucre and calyx), and the fruit is actually a nut (T. S. Elias 1972; W. E. Manning 1978).
The morphology and classification of the family were discussed by W. E. Manning (1978). The female inflorescences and fruits show considerable variation in Latin American and Eurasian taxa.
|1||Branchlets with solid and homogeneous pith; distal leaflets largest; staminate catkins in sessile or pendunculate fascicles, stamens 3-10(-15) per flower; fruits with husks completely or partially dehiscent, nuts smooth, verrucose, or rugulose.||Carya|
|1||Branchlets with chambered pith; leaflets uniform in size or median leaflets largest; staminate catkins sessile, solitary, stamens 7-50 per flower; fruits with husks indehiscent, nuts grooved, ridged, furrowed, or smooth.||Juglans|