Black Walnut (Juglans nigra) · Herb Profile

At a glance

Botanical name: Juglans nigra
Family: Juglandaceae
Part used: Hull, Leaf, Bark
Taste: Bitter, astringent
Temperature: Cool to neutral
Moisture: Drying

No pre-1900 source found for this exact plant and part. The one old reading is for the European walnut, and it describes the kernel rather than the hull, leaf and bark.

Safety at a glance

In pregnancy

Avoid internally (juglone concerns; possible uterine effects); topical use cautious

While breastfeeding

Avoid internal use during breastfeeding — juglone toxicity concerns; topical use cautious.

For children

Older children under guidance, short course for parasitic indications; avoid in infants

Cautions

Juglone is cytotoxic in sustained high doses — short courses only; stains skin and textiles; tyramine (theoretical MAOI) in oxidized hulls

General contraindications

Intestinal obstruction; known walnut-family allergy

Stewardship

Black Walnut (Juglans nigra) is cultivated and wild in North America. Green hulls stain intensely. Stewardship: a tree of complete utility — wood, nuts, hulls, bark all used; teach it as a stewardship model of full-plant medicine.

In the traditional record

Black Walnut (Juglans nigra) — the green hulls used by Cherokee and other eastern North American peoples for skin conditions and intestinal parasites; documented in King's American Dispensatory as an alterative, anthelmintic, and astringent, with the related European species (Juglans regia) recorded by Dioscorides and Culpeper.

Which herbs suit your body?

The same herb can calm one person and wire another. Our free assessment reads your pattern across temperature, moisture and tone, then matches herbs to it.

Take the free assessment Open Black Walnut in the Apothecary

Teaching children at home? Eden's Table builds a full herbalism curriculum around plants like this one.

Educational use

The Apothecary is educational and does not constitute medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before changing what you take, especially if you are pregnant, nursing, taking medication, or managing a diagnosed condition.

On our sources

These entries draw on public-domain materia medica, most of it published before 1900, alongside a smaller number of modern reference works. Energetic qualities such as warming, cooling, drying and moistening are a traditional framework for describing how a plant behaves in the body, not a laboratory measurement. Where a period source states one, we cite it. Where none does, and for many North American herbs none exists, the value reflects modern herbal consensus rather than a historical text. When we cannot support a caution with real evidence, we say nothing rather than guess.