Materia Medica

Wild Indigo (Baptisia tinctoria) — Yellow Wild Indigo, Horsefly Weed

September 29, 2026

Wild indigo, Baptisia tinctoria, is a yellow-flowered eastern North American perennial with dye, ethnobotanical and historic Eclectic-medicine uses. This guide separates that history from modern evidence, explains quinolizidine-alkaloid safety, and clarifies why common-cold research on multi-herb combinations does not prove Baptisia works alone.

September 29, 2026

Wild lettuce, Lactuca virosa, has a long European history as a bitter sedative and analgesic herb whose dried milky latex was called lactucarium or “lettuce opium.” This guide explains why that nickname is misleading, reviews lactucin and lactucopicrin research, documented human toxicity, identification, and safety without providing home extraction or dosing instructions.

September 29, 2026

Wild yam, Dioscorea villosa, is a native North American medicinal vine whose rhizome contains steroidal saponins including diosgenin. This guide explains its traditional use, the pharmaceutical history of diosgenin, the persistent but incorrect “natural progesterone” claim, menopause research, identification, sourcing and safety.

September 29, 2026

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.

September 29, 2026

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.

September 28, 2026

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.

September 28, 2026

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.

September 28, 2026

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.

September 28, 2026

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.

September 28, 2026

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.

September 28, 2026

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.

September 28, 2026

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.