Scientific Classification:

Kingdom Plantae
Division Magnoliophyta
Class Magnoliopida
Order Fagales
Family Juglandaceae
Genus Juglans
Species J. nigra
Binomial name Juglans nigra

Other Common Names:

The other common names for the black walnut are American walnut, Carya persica, Carya basilike, Nux persica and Nux regia.


Black walnut (Juglans nigra), also called eastern black walnut and American walnut, is one of the scarcest and most coveted native hardwoods. Small natural groves frequently found in mixed forests on moist alluvial soils have been heavily logged. Walnut is basically native to northern Persia and its Greek names 'Persicon' provides ample hint of its origin. On the other hand, the walnut's other Greek name 'Basilicon' is an indication of the high esteem they held the tree in.

From 'Basilicon', the walnut derived its explicit name 'regia' meaning 'royal'. Again, if Pliny is to be believed, the walnut was also known as "Caryon' - the basis of the name Carya, the Hickory. This was probably owing to the lethargic feeling generated in the mind on smelling the leaves of the tree. However, others are of the view that the walnut got this name owing to the similarity of the kernel to the shape of the human brain. The fruit leaves and bark of the Black Walnut (Juglans nigra) tree offer many benefits. The distinctive tasting nuts are in demand for baked goods and ice cream, but people must be quick to harvest them before the squirrels. The shells are ground for use in many products.


Walnut is a medium to large tree up to 100 feet in height that developes a straight, clear bole with a narrow crown under competition, twigs and branches quite stout. Twigs are stout with monkey-faced leaf scars and a brown chambered pith and the buds are tan, and large with a few pubescent scales. Bark is dark brown to black and deeply grooved.

The leaves are alternate, pinnately compound, 12 to 24 inches long with 10 to 24 leaflets (poorly formed or missing terminal leaflet), leaflets are ovate-lanceolate, finely serrate, and 3 to 3 1/2 inches long, rachis is stout and somewhat pubescent; yellow-green to green above, slightly paler below. Flowers which are monoecious in which the males are single-stemmed catkins, 2 1/2 to 5 1/2 inches long; females on short spikes near twig end, yellow-green in colour, appearing in late spring. The fruit is a large, rounded, brownish black nut with a hard, thick, finely ridged shell enclosing a rich, oily kernel. The kernel is edible and highly nutritious. The nut is enclosed in a solid, non-splitting husk, and is borne on the tree singly or in pairs.


Black walnut (Juglans nigra) is native to south-western Ontario and has been planted as a cultivated tree. It is scattered throughout the central and eastern parts of the United States. Its natural range extends from western Vermont and Massachusetts west through New York to southern Ontario, central Michigan, southern Minnesota, eastern South Dakota and north-eastern Nebraska; south to western Oklahoma and central Texas; excluding the Mississippi River Valley and Delta, it ranges east to north-western Florida and Georgia .


Black walnut is found on fertile, moist sites in the east and central U.S. and is intolerant of shade. Black walnut is sensitive to soil conditions and develops best on deep, well-drained, nearly neutral soils that are generally moist and fertile. Walnut is common on limestone soils and grows especially well on deep loams, loess soils, and fertile alluvial deposits. It also grows well on good agricultural soils that do not have fragipans. Walnut grows slowly on wet bottom land and on sandy or dry ridges and slopes.


Black Walnut can survive on poor sites, but will grow best in rich moist well-drained soil in a sunny location. It has a long taproot which makes large specimens difficult to transplant, but gives established trees tolerance to drought. The seed is best sown as soon as it is ripe in individual deep pots in a cold frame. It should be protected from mice, birds, squirrels etc. The seed usually germinates in late winter or the spring. Plant out the seedlings into their permanent positions in early summer and give some protection from the cold for their first winter or two. The seed can also be stored in cool moist conditions (such s the salad compartment of a fridge) over the winter and sown in early spring but it may then require a period of cold stratification before it will germinate.

Flowering Season

lack walnut flowers generally begin to appear about mid-April in the South and progressively later until early June in the northern part of the natural range.

Pests and Diseases

The most common problems in walnut occur by walnut caterpillar (Datana integerrima) and the fall webworm (Hyphantria cunea). They are commonly found eating the leaves. Boring insects are the ambrosia beetle (Xylosandrus germanus), which may introduce a Fusarium fungus into the tree, causing dieback and resprouting from the base of the tree; the flatheaded apple tree borer (Chrysobothris femorata), which feeds in the phloem and outer sapwood area as larvae and on the foliage as adults; the walnut curculio (Conotrachelus retentus), which damages developing nuts when the larvae bore into them and cause great losses during the so-called "June drop" of walnuts. Walnut anthracnose, caused by the fungus Gnomonia leptostyla, is a leaf spot disease. Another important foliage disease is target leaf spot which is caused by the fungus Cristulariella pryamidalis and is responsible for premature defoliation. Important stem diseases caused by fungi are the Fusarium cankers caused by several species of Fusarium and the perennial target canker (Nectria galligena) commonly known as Nectria canker (49). Cankers usually occur on the main stem where a branch broke off and left an open wound.

Parts Used


Leaves, nut, hull and the inner bark are the most commonly used parts of the walnut tree for its commercial and medicinal purposes.

Medicinal Applications


• Taken internally, Black Walnut helps relieve constipation, and is also useful against fungal and parasitic infections.

• The walnut leaves can be used as an infusion as well as eyewash.

• The brown stain found in the green husk contains organic iodine which has antiseptic and healing properties.

• Black Walnut is also used to balance sugar levels and burn up excessive toxins and fatty materials.

• It may also help eliminate warts, which troublesome growths are caused by viruses.

• A tincture prepared with the walnut leaves and water is useful in treating conjunctivitis as well as blepharitis.

• Rubbed on the skin, Black Walnut extract is reputed to be beneficial for eczema, herpes, psoriasis, and skin parasites.

• The nut is helpful in menstrual dysfunction.

• Black Walnut has the ability to fight against fungal infections, and acts with an antiseptic property which helps fight bacterial infection.

Commercial Applications


• A brown dye is obtained from the nuts, husks and bark.

• The commercially valuable wood is used for furniture and veneer.

• An edible oil is obtained from the seed.

• They are also used as an insecticide against bed bugs.

• The richly flavoured nut meats are used by bakers, candy and ice cream makers.

• The husks are rich in tannin.

• It is used in cabinet making, the interior finishes of houses, furniture, airplanes and ship building.

• The woody shells on the fruits have been used to make jewellery.


The astro reports for the walnut tree say that it is under the influence of the celestial body Sun.

Quotes from History

During World War II, airplane pistons were cleaned with a "nut shell" blaster and this idea was carried into the auto industry; manufacturers used shells to deburr precision gears. Ground shell products are also used to clean jet engines, as additives to drilling mud for oil drilling operations, as filler in dynamite, as a nonslip agent in automobile tires, as an air-pressured propellant to strip paints, as a filter agent for scrubbers in smokestacks, and as a flourlike carrying agent in various insecticides.

Cultural and Religious Significance

The walnut is considered to be sacred and all festivals of the Greek Goddess Diana were organized in the shade of the tree. The Romans associated the walnut with the Juno, the Roman goddess of women and marriage and the wife of Jupiter. This association led to the unique wedding practice of throwing walnuts at the bride and groom as a symbol of fertility. Women often carried walnuts to promote fertility. There is a legend that presumes walnuts were one of the gifts presented to Jesus by the three wise men.

Folklores and Myths

It is believed that walnuts are used to break the power of the past. Folklores says that to Fall Out of Love or if you are having a difficult time leaving a relationship, bathe in a strong brown tea made by boiling nine black walnuts still in their husks boiled in 3 quarts of water until it evaporates down to 1 quart and turns brown. As you bathe, renounce all ties to your former lover, then throw the water out at a crossroads or against a tree. To make the spell stronger, you may write the ex-lover's name on paper, bathe by the light of a candle, and burn the name-paper in the candle flame. Some young men in the French countryside believed the walnut tree to possess aphrodisiac powers and attempted to sneak a leaf into the shoe of a young woman they admired. Along with some items of amusing folklore, the walnut tree holds a few dark superstitions. In seventeenth century Italy there was a walnut tree, the Tree of Benevento that was believed to be the place where witches gathered. According to a legend, the Bishop removed the tree, roots and all, but another witch-haunted tree grew where the original stood. Another legend warns it is unlucky to plant walnut trees too close to a stable because it might bring illness and death to the animals. Even travellers along the road were warned not to choose the walnut tree as a refuge for the night, fearing they may become ill.