Species list


Juglans regia

Persian walnut

Persian walnut, English walnut, common walnut, California walnut (Eng); nogal, noguera (Spa); noguer, noguera (Cat); intxaurrondoa (Baq); nogueira (Glg); nogueira (Por).


DID YOU KNOW...? Walnut stew cooked with maize meal and dried figs was a traditional breakfast in many Canarian homes.


As its specific name indicates, the walnut is a regal, majestic plant that can be up to 25 or 30 m tall, and which has a broad crown that casts a deep shade under the canopy. The bark is silvery grey and sometimes cracked longitudinally. The leaves are deciduous, alternate and compound with 5 to 9 leaflets, always in an uneven number (odd-pinnate). They are oval or lanceolate, irregular, and have an entire margin. The male and female flowers are separated on the tree; the female blooms are inconspicuous, but the male blossom is showier and arranged on long hanging stems known as catkins, which favour the wind-dispersal of pollen. The fruits are walnuts. They are surrounded by a fleshy, smooth green cover that dries out when ripe at the end of summer or in autumn, becoming brown or purplish in colour.


The walnut adapts well to any soil type, although it prefers deep, moist (but not waterlogged) soils in order to develop its powerful root system. It withstands the cold well, but does not like late frosts, excessive drought or severe pruning. In the Canaries it is frequent on the upper midslopes, or medianías (zones between altitudes of 600 and 1500 m), or even in summit zones. It is rare to find other plants growing beneath its shade, as the remains of fallen leaves contain tannins and other compounds that inhibit the germination and growth of other species.


According to various authors, this species is originally from Southeast Asia or China; but, since it has been cultivated for thousands of years, its natural range has become blurred. The Greeks and the Romans cultivated this tree across Europe for its fruits and ornamental character. In the Canary Islands it is only considered to have become established in the wild on Gran Canaria.