Common walnut (Juglans regia)

Common walnut (Juglans regia)

Common names: Persian walnut, English walnut


The common walnut is a large monoecious tree with light-grey bark and sparse foliage, belonging to the walnut (Juglandaceae) family. Its pinnately compound leaves are made up from 5 to 9 long, ovate leaflets. The elongated leaflets have intact margins and, if crushed, they have a strong aromatic scent. The male flowers form drooping catkins, the female flowers are grouped into clusters of 2 to 5. The trees bloom in April-May. Its fruits are the walnuts covered in a spherical or oval shell.

It is a species originating from the Balkans, requiring warm and moderately humid soils.


The walnut tree foliage (Juglandis folium) is collected for medical purposes. In addition, one can also use the unripe green husks and the inner dividing walls. The leaves are collected when fully- developed, they are ripped off the rachis. The green husks are collected during the walnut harvest period.

Active substances:

Both the walnut leaves and the husks contain naphthoquinone derivatives (juglone), flavonoids, tannins, a small quantity of essential oils and vitamin C.


Due to its anti-inflammatory, bactericidal and fungicidal effects, it is used both externally and internally. Due to its slightly disinfectant, contractile effects, it is used in tea mixtures against enteritis and diarrhea. In traditional medicine, walnut has been used for a long time due to its wound-healing effects. Walnut leaf infusions are used as compresses or for rinsing ulcerations, carbuncles, inflammatory wounds and eczema. The cosmetics industry uses juglone transformation products for some hair dyes and sun protection oils. Walnut oil is rich in unsaturated fatty acids and thus it is a useful ingredient in an atherosclerotic diet.