English Walnut (Persian Walnut, Common Walnut)
Kingdom: Plantae > Division: Tracheophyta > Class: Magnoliopsida > Order: Fagales > Family: Juglandaceae > Genus: Juglans > Species: Juglans regia · Juglandaceae (Walnut family) · Pinnately compound (odd-pinnate), Deciduous
Species
Juglans regia
Leaf Type
Pinnately compound (odd-pinnate), Deciduous
Family
Juglandaceae (Walnut family)
Shape
Elliptic to ovate or oblong leaflets with acute to acuminate tips
Size
Individual leaflets are approximately 3 to 6 inches long (7-15 cm) and 1.5 to 3 inches wide; entire compound leaf spans 10 to 16 inches in total length.
Margin
Entire (smooth) to slightly undulate, unlike many other walnut species which have serrated edges.
Arrangement
Alternate foliage arrangement along sturdy twigs; leaflets are arranged opposite to subopposite with a single terminal leaflet.
Rarity
Very Common (frequently cultivated for timber and agricultural walnut production).
Color & Pattern
Vibrant medium to bright green upper surface, lighter pale green underneath; yellow-green prominent central midrib and lateral veins.
Venation Pattern
Pinnate venation with a very distinct midrib and evenly spaced secondary veins curving toward the margins.
Texture & Surface
Smooth, slightly leathery (coriaceous) to papery surface; virtually glabrous (hairless) on the upper surface when mature.
Description
Juglans regia is a large deciduous hardwood tree growing up to 25–35 meters tall with a broad, rounded canopy and thick, light gray bark that develops deep furrows with age. Its foliage consists of large, aromatic odd-pinnate compound leaves, typically bearing 5 to 9 large, smooth-edged leaflets. In autumn, the leaves turn yellow-brown before shedding. It produces green husked fruits enclosing the familiar edible walnut.
Key Features
Pinnately compound leaves with 5-9 leaflets; entire (smooth) leaflet margins which distinguish it from Black Walnut; strongly aromatic foliage when crushed; thick greenish-gray twigs with chambered pith.
Habitat
Thrives in deep, rich, well-drained loamy soils with full sun exposure; commonly planted in orchards, parks, residential gardens, and rural valleys.
Geographic Range
Native to Central Asia and Southeastern Europe (from the Balkans to Southwest China); widely cultivated across temperate regions of Europe, North America, East Asia, and South America.
Condition Notes
The foliage appears healthy with vibrant green color. Minor superficial leaf gall or insect damage visible on the upper left leaflet tip, and slight browning at the apex of the central leaflet, but overall condition is Good.
Interesting Facts
When crushed, the leaves release a distinctive pleasant citrusy-spicy scent. The tree secretes a natural herbicide called juglone into the soil, which inhibits the growth of certain competing plants nearby.
Medicinal & Uses
Highly valued worldwide for its edible nuts (walnuts) rich in omega-3 fatty acids, high-grade fine hardwood timber for furniture and gunstocks, and traditional medicinal extracts from leaves and green husks used as astringents and natural dyes.
Ecological Role
Provides food for squirrels, rodents, and birds; hosts larvae of various moth species. Highly valued in agricultural forestry.
Similar Species
Juglans nigra (Black Walnut) which has 10-23 finely serrated leaflets and lacks a prominent terminal leaflet; Carya species (Hickories) which typically have serrated leaflets.
Foraging Tips
Look for large compound leaves with smooth edges and 5-9 leaflets. Rubbing a leaf produces a distinct spicy aromatic aroma. Green walnuts can be gathered in early summer for pickling or liqueur (like Nocino), while mature nuts ripen in early autumn.
Toxicity Warning
Mildly Toxic to certain livestock (especially horses) if exposed to wood shavings/mulch. Produce juglone which exhibits allelopathic toxicity to sensitive neighboring plants like tomatoes, potatoes, and azaleas.