The mature common walnut is a 30-meter tree belonging to the Juglandaceae family. It has a large, straight trunk whose brown color turns to gray when the tree reaches maturity. The trunk bears upright branches that open out to form a broad, rounded crown.
The leaves of the common walnut are deciduous and alternate. Up to 15 cm long, each leaf consists of 7 to 9 leaflets with smooth margins. The common walnut is a monoecious tree with separate sexes, pollinated by the wind. The tree’s first inflorescences generally appear in April.
Male inflorescences form pendulous catkins on which numerous small green flowers cling. These basket-shaped flowers are borne on the previous year’s twigs. Resembling small amphorae, the female flowers are usually grouped in spikes. Also green in color, they grow at the tip of the current year’s shoots.
The common walnut doesn’t produce fruit until its fifteenth year. Green, then brown, the tree’s fruit is a drupe covered with a smooth, fleshy husk. Each fruit contains a hard, woody nut divided into 4 lobes. Edible, walnuts are known for their high oil content. Walnuts are generally harvested in early autumn.

Originally from Persia, the common walnut has long since adapted to the European climate. It can be found in Italy, Greece and France, where it can grow at altitudes of up to 1,000 meters. Walnut is easy to grow. Planting at the end of November is recommended. The common walnut is not very demanding in terms of soil type: it adapts easily to all types of soil, provided it is planted at a good depth. In fact, the depth of the soil must allow the tree’s taproot system to
develop perfectly. The common walnut appreciates sunny but slightly shady locations. What’s more, this tree is exceptionally hardy: it can withstand sub-zero temperatures, and young specimens tolerate pruning well. However, it is advisable to stop pruning once the tree reaches adulthood.

The benefits of walnut leaves have always been recognized in phytotherapy. Picked in early summer, the leaves contain a number of active substances. They contain tannins, especially ellagitannins, vitamin C and flavonoids, including quercetol and hyperoside. They also contain a good dose of naphthoquinones, including juglone and hydrojuglone, as well as phenolic acids: caffeic, salicylic, ferulic, p-coumaric, gallic and chlorogenic. These different elements act synergistically to support the function of the digestive tract. They also help maintain intestinal regularity. These same active ingredients help to physiologically eliminate excess fluids and increase the body’s physiological resistance. This is particularly the case when the organism
has to cope with severe environmental conditions.
The leaves of the common walnut tree are today exploited and offered in a wide variety of formats.