Juglans nigra, commonly known as black walnut, is a deciduous tree in the family Juglandaceae native to eastern and central North America, thriving in temperate forests with deep, well-drained soils. The medicinally used green hull is intensely bitter and astringent with a sharp tannic character and dark staining quality due to its high phenolic & quinone content. It's recognized for antimicrobial, antifungal, antiparasitic, astringent, antioxidant, and emerging anti-inflammatory activity, all largely attributed to juglone, tannins, flavonoids, and other polyphenols. Traditionally, this herb has been used for intestinal parasites, fungal skin infections, mild diarrhea, and topical skin conditions where tissue tightening. A 2019 in vitro study evaluating black walnut extracts demonstrated the inhibition of proinflammatory cytokine production in human promonocytic cells, supporting its anti-inflammatory potential and suggesting relevance in conditions characterized by excessive inflammatory signaling PMID: 31607915. Historically, its hull’s powerful pigment was used by Indigenous communities as well as early American settlers as a permanent brown dye for textiles and hair. Its tree is famously allelopathic - releasing juglone into the surrounding soil to suppress any competing plants, a chemical defense strategy that mirrors this plant's potent antimicrobial chemistry.