Juglans regia

English walnut, or common walnut is in the Juglandaceae family and is an Old World walnut tree species native to the Balkans eastward to the Himalayas and southwest China. The largest original forests are in Kyrgyzstan.

The English walnut's large nut and thin shell have led it to become the main commercial tree for growing most of the world's walnuts. Two-thirds of global supply of English walnuts is grown in California's Central Valley and in Coastal Valley, with more than 30 varieties of J. regia grown there.

• Leaves are alternate, pinnately compound, with only 5–9 leaflets, 25–40 cm long, paired alternately with one terminal leaflet. The largest leaflets are the three at the apex.
• Species is monoecious. Male flowers are in drooping catkins 5–10 cm long, and female flowers are in clusters of 2-6 on a short stem, with fuzzy nondescript flowers.
• Leaf scar has 3 prominent bundle scars in the shape of a "happy face", no hairy eyebrow; the pith is chambered, chocolate brown colour.
• Walnuts in the fall are in clusters of 2–6, with a green, semi-fleshy husk and a brown, corrugated walnut. Nut shell is relatively thin, fewer shallow furrows, with fleshy, corrugated walnut inside.