Materia Medica

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...
Yellow Root (Xanthorhiza simplicissima) — Shrub Yellowroot, Brook-Feather
Yellow root (Xanthorhiza simplicissima) is a native eastern North American shrub with intensely yellow, berberine-containing roots and a documented history in Cherokee, Catawba and Appalachian plant use. This guide covers correct identification, traditional uses, phytochemistry, research limits, cultivation, sustainable sourcing and safety. Read more...
Yerba Santa (Eriodictyon californicum) — Holy Herb, Mountain Balm
California yerba santa (Eriodictyon californicum) is an aromatic evergreen shrub native to California and Oregon with a long Indigenous and regional history of respiratory use. This guide covers correct identification, traditional cough and cold use, modern flavanone chemistry, sterubin research, cultivation and the limits of current safety and clinical evidence. Read more...
Yew (Taxus spp.) — English Yew, Pacific Yew
Yews (Taxus spp.) are ancient evergreen trees and shrubs with major historical and pharmaceutical importance—but their needles, bark and seeds contain dangerous taxines that can cause fatal cardiac poisoning. This safety-focused guide covers identification, toxicology, Pacific yew and paclitaxel history, and why crude yew must never be used as a home cancer remedy. Read more...
Ylang Ylang (Cananga odorata) — Perfume Tree, Macassar Oil
Ylang ylang (Cananga odorata) is a tropical Annonaceae tree whose intensely fragrant flowers yield one of perfumery’s best-known essential oils. This guide covers botanical identity, traditional use, essential-oil chemistry, small human aromatherapy studies, contact-allergy risk, cultivation and practical safety. Read more...
Yohimbe (Corynanthe johimbe) — Yohimbine, Johimbe
Yohimbe is a West and Central African tree whose bark contains yohimbine, a pharmacologically potent alpha-2 adrenergic antagonist. This guide distinguishes traditional bark from purified yohimbine, reviews sexual-health research, documents major supplement-label variability, and explains cardiovascular, neurologic and medication-interaction risks. Read more...
Yucca (Yucca schidigera) — Mojave Yucca, Soapweed
Mojave yucca (Yucca schidigera) is a desert shrub-tree traditionally used for food, fiber, washing and regional medicine. This guide covers correct identification, steroidal saponins and yuccaols, food-use regulation, the limited human evidence behind arthritis and cholesterol claims, cultivation, sustainability and safety. Read more...
Globe Artichoke (Cynara cardunculus; syn. Cynara scolymus): Food, Artichoke Leaf Extract, Digestion, Cholesterol Research & Safety
Globe artichoke is a Mediterranean food plant now treated botanically within Cynara cardunculus; Cynara scolymus remains a familiar synonym in older herbal and clinical literature. This guide distinguishes the edible flower bud from medicinal leaf preparations, reviews dyspepsia and cholesterol research, explains cynarin and caffeoylquinic acids, and covers biliary and allergy cautions. Read more...
Editorial illustration labeled Soybean and Glycine max, showing trifoliate leaves, flowers, pods and seeds
Soybean (Glycine max): Whole-Plant Guide to Food, History, Research & Safety
Soybean (Glycine max) is an East Asian food legume used for tofu, miso, tempeh and edamame. Explore parts used and avoided, three recipes, nutrition research, allergy safety, history and symbolism. Read more...