Materia Medica

Green Tea (Camellia sinensis) — Green Tea Leaf, Matcha
A guide to Camellia sinensis green tea covering caffeine, catechins, tea processing, research, iron absorption and concentrated-extract liver safety. Read more...
Milk Thistle (Silybum marianum) — Holy Thistle, Marian Thistle
A guide to Silybum marianum covering milk thistle fruit, silymarin, liver research, extract differences, Asteraceae allergy and safety. Read more...
Thyme (Thymus vulgaris) — Common Thyme, Garden Thyme
A guide to Thymus vulgaris covering thyme's culinary and respiratory traditions, cough-product research, essential-oil chemotypes, irritation risk and safety. Read more...
Turmeric (Curcuma longa) — Indian Saffron, Haldi
A guide to Curcuma longa covering turmeric food traditions, curcumin research, absorption-enhanced supplements, gallbladder, bleeding and kidney-stone cautions. Read more...
Ragwort (Jacobaea vulgaris) — Tansy Ragwort, Stinking Willie, Benweed
Tansy ragwort, also called common ragwort, is Jacobaea vulgaris (formerly widely known as Senecio jacobaea). This is a toxicity and identification article: the plant contains unsaturated pyrrolizidine alkaloids associated with serious liver injury in people and livestock. No medicinal dosing or preparation instructions are provided. Read more...
Tansy (Tanacetum vulgare) — Common Tansy, Bitter Buttons, Golden Buttons
Common tansy is a historic European herb with old culinary, antiparasitic and household uses, but modern internal use is limited by unpredictable essential-oil chemotypes and thujone neurotoxicity. This guide separates true Tanacetum vulgare from tansy ragwort and feverfew, explains U.S. food restrictions, and reviews identification and safety. Read more...
Tarragon (Artemisia dracunculus) — French Tarragon, Estragon
Tarragon is a classic culinary Artemisia with distinct French and Russian forms, a long digestive tradition, and limited but real human metabolic research. This guide explains its botany, flavor chemistry, estragole and methyleugenol safety concerns, and why culinary use is different from concentrated extracts and essential oil. Read more...
Tea Tree (Melaleuca alternifolia) — Narrow-Leaved Paperbark, Snow-in-Summer
Tea tree oil is a steam-distilled topical essential oil from Melaleuca alternifolia with human research for acne and some superficial fungal conditions. This guide separates topical evidence from laboratory claims, explains why the oil should not be swallowed, and covers oxidation, contact allergy, storage and the debated endocrine-disruption claim. Read more...
Illustrated thunder god vine with the labels Thunder God Vine and Tripterygium wilfordii at the top; not a field identification photograph
Thunder God Vine (Tripterygium wilfordii) — Lei Gong Teng, Yellow Vine
Thunder god vine (Tripterygium wilfordii), or Lei Gong Teng, has clinical research in rheumatoid arthritis and kidney disease but serious toxicity risks. Explore its traditional context, research, plant-part dangers, fertility... Read more...
Tobacco (Nicotiana tabacum) — Common Tobacco, Virginia Tobacco
Nicotiana tabacum is the principal cultivated tobacco species, a culturally important American plant containing highly addictive and potentially toxic nicotine. This guide covers botany and traditional context, nicotine poisoning, green tobacco sickness from skin exposure, the health effects of tobacco use, and current U.S. tobacco-product regulation without providing smoking, curing or nicotine-extraction instructions. Read more...
Tonka Bean (Dipteryx odorata) — Coumara Nut, Cumaru
Tonka bean is the intensely fragrant seed of the South American tree Dipteryx odorata and one of the original natural sources of coumarin. This guide reviews its botany, fragrance and traditional uses, explains human coumarin hepatotoxicity, and states the U.S. food restriction accurately: foods containing added coumarin from tonka beans or tonka extract are deemed adulterated. Read more...
Tormentil (Potentilla erecta) — Erect Cinquefoil, Bloodroot
Tormentil, Potentilla erecta, is a tannin-rich European rhizome traditionally used for mild diarrhea and minor inflammation of the mouth. This guide separates it from creeping cinquefoil and North American bloodroot, reviews EMA-recognized traditional use, modern human and laboratory research, safety, identification and sustainable rhizome sourcing. Read more...