The common name walnut derives from Old English wealhhnutu, literally foreign nut . The Latin name for the walnut was nux Gallica, Gallic nut . The generic name comes from Latin juglans. Juglans regia is a large deciduous tree, attaining heights of 2535 m (80 to 120 ft), and a trunk up to 2 m (6 ft) in diameter, commonly with a short trunk and broad crown, though taller and narrower in dense forest competition. It is a light-demanding species, requiring full sun to grow well. The bark is smooth, olive-brown when young and silvery-grey on older branches, and features scattered broad fissures with a rougher texture. Like all walnuts, the pith of the twigs contains air spaces; this chambered pith is brownish in color. The whole fruit, including the husk, falls in autumn; the seed is large, with a relatively thin shell, and edible, with a rich flavor.