The walnut is a tree that can reach the 20-25 meters of height and whose diameter can measure from 1 to 2 meters. Its bark is silver-grey, smooth on the young stems as the longitudinal cracks appear very late. The branches are dark red when young and then turn grey-silvery like the trunk. The stem is straight, vigorous and subdivides in a few main branches forming an ample, rounded and dense foliage. The fruit is an oval drupe which opens when ripe with a length of about 3-4 cm and a width of little less. The fruit is constituted by a greenish-yellow pericarp commonly called hull which detaches itself when dried. The endocarp is a woody shell with two irregularly grooved valves. Inside the endocarp lies the seed or kernel divided by a false septa. The seeds ripen between September and October.