Introduction of Black Walnut:American walnut or Eastern black walnut.
✵The article gives records of the herb Black Walnut, its English name, Latin name, common names, property and flavor, its botanical source two plant species, ①.Juglans nigra L., with a detailed introduction to the botanical features of this plant species, the growth characteristics, and ecological environment of this plant species, the features of the herb Black Walnut, its pharmacological actions, medicinal efficacy, and administration guide.
Black Walnut(American walnut).
English Name: Black Walnut
Latin Name: Juglans nigra L.
Common Names: American walnut, Eastern black walnut.
Property and flavor:
Brief introduction: Black Walnut is the nuts of Juglans nigra, a native tree that grows in central and east of USA (the United States of America), there are no recognized subspecies, varieties, or forms. Black walnut and butternut (Juglans cinerea) often grow together, but never cross naturally.
Botanical source: Common herbal classics defined the herb Black Walnut as the inner bark and other parts of the species (1). Juglans nigra L. It is a plant species of the Juglans genus, the Juglandaceae family (walnut family). The inner bark, husks, leaves, and nuts are used medicinally. This commonly used species is introduced:
(1).Juglans nigra L.
Botanical description: Juglans nigra is a plant of the Juglandaceae family and Juglans genus, it is also known as American Black Walnut, a deciduous tree and the tree grows up to 30 meters high, but ordinarily it grows to around 25 meters high, round crown or cylindrical. Trunk bark is grey-black and deeply furrowed, long and smooth, with deep longitudinal cracks. The bark on young trees is dark and scaly but becomes darker with rounded intersecting ridges on mature trees. The root system usually consists of a deep taproot and several wide-spreading lateral roots. Branches are grayish-brown or dark brown, with short hairs, and broad triangular buds. The pith of the twigs contains air spaces. Odd-pinnate compound leaves, 15 to 23 leaflets, very short stalks, irregular serrations on the margin, glandular hairs on the abaxial surface. The female inflorescence has 2~5 flower clusters. The fruit is spherical, light green, with small protrusions on the surface, and covered with hair. The nuts are round, slightly flat, slightly pointed at the tips, and have irregular deep grooves on the shell surface, the fruit falls in October. The shells of the seed are thick and hard to crack.
The flowering period of Juglans nigra is about mid-April in the southern part of its geographic range and mid-June in the northern part of its range. The fruit ripens in September or October of the same year, dropping shortly after the leaves fall.
The American Black Walnut is one of the best-recognized hardwood forest species in the world and is considered to be a fruit tree species with high economic value in USA. Its wood structure is compact, has high mechanical strength, texture, color appearance, and easy processing, suitable for plywood, furniture, craft carving, architectural decoration, and other excellent materials. Traditionally, the hulls are boiled to make a wool dye.
Ecological environment: Black walnut got found throughout the eastern USA, while its primary native region is the Midwest and the east-central USA, it is cultivated there and in North America as a forest tree for its high-quality wood, the black walnut got introduced into Europe in 1629 A.D., it also grows in North Europe countries, and it is also distributed in other areas of North America and South America, Black walnut is also cultivated in Hawaii of USA.
Growth characteristics: Juglans nigra grows in closed forests, and needs full sun for optimal growth and nut production, it is a common weed tree found along roadsides, fields, and forest edges in the eastern USA. The adaptability of black walnut to the soil is also strong. It can grow in various soils with a pH (pH scale:acidity-basicity) of 4.6~8.2, but the growth in different soils varies greatly. The best is sandy loam soil or alluvial soil. The required soil layer depth is 3 to 4 meters, neutral or slightly acidic, ventilated, and drained. It prefers full sun and wet to dry loam or sandy high acidic to slightly alkaline soil. It grows well on rich bottom lands, in moist, fertile coves, and on lower slopes. Its survival, growth, and quality in less fertile sites is problematic.
Pharmacological actions: ①.astringent property; ②.antifungal property; ③.anti-tumor activity; etc.
Related studies proposed the astringent property of black walnut mainly comes from its component juglone, which is found in the hulls and leaves, juglone has astringent property and help shrink tissues and prevent oozing, it is useful for treating some wounds, mouth sores, and throat sores, irritations from hemorrhoids, eliminate inflammation in the intestines and relieve loose stools. Due to its antifungal property, juglone or its leaves and hulls could be used for fungal skin infections such as ringworm, or oral bacteria and infectious disease in the mouth. Scientists found the leaves and fruit hull has anti-tumor activity, and the polysaccharides from the nutshells could inhibit HIV (human immunodeficiency virus) in the test tube.
Medicinal efficacy: The black walnut was used in North America traditionally by Native Americans, its juice of the nut husks was used for the treatment of ringworm, and colic, the poultice of the husk was used to relieve skin inflammation, and tea of the inner bark was used to treat constipation and induce vomiting, leaf tea was used to fight bed bugs (Cimex lectularius: small, flat, parasitic insects that feed solely on the blood of people and animals while they sleep). It is recommended by contemporary herbalists as a mild laxative for constipation, to improve digestion, and bowel regulation, and to fight internal fungal, bacterial, and parasitic infections, hull saps or leaf infusion is recommended to apply coating on the skin for warts, fungal infections, herpes, eczema, psoriasis, bruising, and other skin ailments.
Administration of Black Walnut (American walnut):
Administration Guide of Black Walnut (American walnut)
Herbal classic books:
The recommended dosage of black walnut, saps are taken in dosages of 10~20 drops daily. Capsules of 500 mg size made from the hulls are advised taken three times daily. Externally, saps or poultice are applied twice a day.
Contraindications, Precautions and Adverse Reactions: There is not much is known about the potential toxicity of black walnut preparations, although no reports of serious harm appear recently. But horses develop adverse reactions when exposed to black walnut shavings, laminitis, swelling, fast breathing, and other signs. Black walnut pollen has caused moderately severe allergic reactions in sensitive individuals. The plant has occasionally been known to cause contact dermatitis in humans.
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1.Introduction of Black Walnut:American walnut or Eastern black walnut.