Materia Medica

Yarrow (Achillea millefolium) — Milfoil, Soldier's Woundwort, Nosebleed

October 3, 2026

A guide to Achillea millefolium covering yarrow identification, traditional wound and digestive use, Asteraceae allergy, pregnancy cautions and folklore.

October 3, 2026

A guide to Ilex paraguariensis covering yerba mate culture, caffeine, very-hot beverage safety, smoke-drying and PAHs, research and precautions.

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 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.

September 28, 2026

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.