Materia Medica

Juglans nigra (Black Walnut), realistic botanical photo
Black Walnut (Juglans nigra) — American Walnut, Eastern Black Walnut
A whole-plant guide to Black Walnut (Juglans nigra), covering edible nuts, green hull and leaf traditions, juglone, evidence limits, tree-nut allergy and supplement safety, dyeing, cultivation and folklore. Read more...
Wheatgrass (Triticum aestivum) with fresh blades and wheatgrass powder
Wheatgrass (Triticum aestivum) — Common Wheatgrass, Wheat Grass
A whole-plant guide to wheatgrass (Triticum aestivum), including the young grass stage, mature wheat plant, leaves and grain, cut-and-sifted and powdered forms, nutrition, everyday use, growing, storage and gluten considerations. Read more...
White Willow (Salix alba) — European Willow, Common Willow
A guide to Salix alba and related willow bark covering salicin, pain research, aspirin differences, bleeding cautions and folklore. Read more...
Witch Hazel (Hamamelis virginiana) — Spotted Alder, Winterbloom
A guide to Hamamelis virginiana covering witch-hazel bark and leaf, topical distillates, tannins, alcohol-containing products, research and safety. Read more...
Wahoo (Euonymus atropurpureus) — Eastern Wahoo, Burning Bush
Eastern wahoo is a native North American shrub or small tree with striking pink-red fruit and a place in historical American materia medica. Because all parts can be poisonous if ingested and may cause gastrointestinal and cardiac effects, this article focuses on identification, history, ecology and safety rather than home dosing. Read more...
Wintergreen (Gaultheria procumbens) — Teaberry, Checkerberry, Boxberry
Wintergreen, Gaultheria procumbens, is an eastern North American evergreen groundcover whose leaves and oil are strongly associated with methyl salicylate. This guide separates traditional leaf and berry use from concentrated wintergreen oil, reviews topical pain traditions and modern toxicology, and explains why essential-oil ingestion or excessive topical exposure can cause serious salicylate poisoning. Read more...
Wood Betony (Betonica officinalis) — Bishop's Wort, Lousewort
Wood betony is an old European medicinal herb now accepted botanically as Betonica officinalis, though Stachys officinalis remains common in herbal literature. This guide covers identification, traditional headache and digestive uses, modern phytochemistry, the limits of human evidence, safety and cultivation. Read more...
Wormseed (Dysphania ambrosioides) — Epazote, Mexican Tea
Wormseed, better known in the kitchen as epazote, is now botanically accepted as Dysphania ambrosioides; Chenopodium ambrosioides is an older familiar synonym. This guide separates culinary leaf use from historical vermifuge use, examines ascaridole research, and explains why concentrated essential oil requires serious safety caution. Read more...
Wormwood (Artemisia absinthium) — Absinthe, Green Ginger
Wormwood (Artemisia absinthium) is an intensely bitter European herb with a long digestive, vermifuge and absinthe history. This guide separates traditional whole-herb use from thujone-rich essential oil, reviews modern pharmacology and limited clinical research, and explains the plant’s major safety concerns. Read more...