The walnut tree can grow up to 25 m high, the 40 cm long, green, glossy leaves are pinnate. The fruit, the walnut, is a spherical drupe with a fleshy shell that turns dark brown when ripe and has a hard nut shell.
The dried leaves (walnut leaves - Juglandis folium) are used phytotherapeutically.
Studies indicate an antiproliferative activity of the proteins and protein hydrolysates contained in walnuts: walnut protein hydrolysates showed an antiproliferative effect on breast cancer, colon cancer cell lines, carcinoma cells of the prostate and also leukemia, as well as melanoma cells.