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Botanical illustration of Black Walnut

Plate II · Hull

Black Walnut

Juglans nigra

The green outer hull of a native North American hardwood, rich in tannins and historically prized as a natural dye.

Type
Hull
Family
Juglandaceae
Origin
Eastern North America

Black walnut hull is the thick green husk around the nut of Juglans nigra, a tall hardwood native to eastern North America that is valued for its dark timber and rich nuts. The hull darkens as it ripens, and anyone who has handled one knows it stains skin a deep brown that lasts for days.

How black walnut is prepared

For botanical products, the hulls are typically harvested while still green, then dried and powdered or extracted. The dried hull is very different from the edible nut kernel inside, and labels should make clear which part is used. In ASPHODEL Botanical Complex, the hull is paired with wormwood and clove.

Tradition, research, and what is established

We keep these three things separate, because they are not the same.

Traditional use

Black walnut hulls were used as a dye for cloth and hair, and appear in North American folk herbalism.

Preliminary research

The hull contains juglone, a compound that suppresses the growth of many nearby plants, along with tannins and other polyphenols. Laboratory interest in these compounds does not establish effects in people.

Established

Juglone’s effect on neighbouring plants is well documented in horticulture. Tree-nut allergy considerations should be confirmed against supplier documentation.

Reading a supplement label

On a supplement label, look for three things: the scientific name (Juglans nigra), the part used (typically the green hull), and the amount per serving listed in the Supplement Facts panel. Those details, taken from the supplier’s documentation, tell you more about a product than any marketing claim.

Black Walnut in the ASPHODEL collection

In the ASPHODEL collection, you will find this ingredient in ASPHODEL Botanical Complex. Each product page lists its ingredients and label details from verified supplier documentation, and the Botanical Journal explores the history and research behind the plants and fungi we work with.

Further reading on black walnut

Botanical reference: Juglans nigra on Wikipedia

This page is educational and describes the history and characteristics of a botanical. It is not medical advice and does not describe the effects of any ASPHODEL product.

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