Walnut, Latin name Juglans regia L. ("Flora of China"), English name: English Walnut,Persian Walnut, Chinese alias: walnut.

Walnut seed kernel is high in oil content, edible or oil extraction, as a strong agent for chronic bronchitis, asthma, etc.; wood is solid, can be made of gun butts, etc.; endocarp and bark rich in tannins; walnut shells can be made of activated carbon. Seeds contain fatty oil, protein, sugar; leaves contain volatile oil, gum, tannin, gallic acid, hydrogenated walnut leaf ketone. Due to cultivation for a long time, there are many varieties; there are also many varieties produced in China, and those species named by Dode, most of which have indistinguishable intermediate types or are based on features that are not stable enough or are too small to be characterized as independent species, such as thin-shelled walnuts produced in Yunnan Province, named by Dode as J. dulcisiana, which can only be regarded as a cultivated variety of walnut.