Materia Medica

Shiso (Perilla frutescens) — Perilla, Beefsteak Plant, Japanese Basil
Shiso is a culinary variety of Perilla frutescens, not a completely separate species. This guide separates shiso leaves from perilla seed oil and concentrated extracts, reviews East Asian food and herbal traditions, human allergy research, omega-3-rich seed oil, and the often-misunderstood livestock toxicity issue. Read more...
Editorial soapwort botanical illustration labeled Soapwort and Saponaria officinalis at the top
Soapwort (Saponaria officinalis) — Bouncing Bet, Fuller's Herb
Soapwort (Saponaria officinalis) has a history in textile washing and herbal lore. Explore its botany, saponin chemistry, three non-ingestible cleaning recipes, safety and modern cleansing symbolism. Read more...
Editorial illustration labeled Common Sorrel and Rumex acetosa, showing arrow-shaped leaves and flowering stems
Common Sorrel (Rumex acetosa) — Garden Sorrel, Sour Grass
Common sorrel (Rumex acetosa) is a tart perennial green. Explore identification, parts used and avoided, oxalate safety, three culinary recipes, history and modern folklore. Read more...
Spearmint (Mentha spicata) — Garden Mint, Lamb Mint
Spearmint is a carvone-rich culinary and medicinal mint with a long digestive tradition and several human trials, including research on androgen levels in women with PCOS and standardized extracts for memory and attention. This guide separates ordinary tea from concentrated extracts and essential oil. Read more...
Spilanthes (Acmella oleracea) — Toothache Plant, Eyeball Plant, Jambu
Spilanthes, now accepted botanically as Acmella oleracea, is the famous toothache plant or jambu whose flowers produce a tingling, numbing and mouth-watering sensation. This guide explains the modern taxonomy, spilanthol chemistry, culinary tradition, pain research and safety without turning a traditional toothache remedy into a substitute for dental care. Read more...
St. John's Wort (Hypericum perforatum) — Klamath Weed, Goatweed
St. John’s Wort is one of the best-studied medicinal herbs for mild-to-moderate depression, but also one of the most interaction-prone. This guide reviews the human evidence, hyperforin and hypericin chemistry, CYP/P-glycoprotein drug interactions, photosensitivity, topical traditions, identification and sourcing. Read more...
Stevia (Stevia rebaudiana) — Sweetleaf, Sugarleaf
Stevia rebaudiana is the South American sweetleaf behind modern steviol-glycoside sweeteners. This guide separates traditional whole-leaf use from high-purity steviol glycosides, explains U.S. regulatory distinctions, reviews human metabolic research, and covers cultivation and safety. Read more...
Sumac (Rhus spp.) — Staghorn Sumac, Smooth Sumac, Sicilian Sumac
Sumac is not one single plant. Mediterranean culinary sumac comes mainly from Rhus coriaria, while North American smooth and staghorn sumacs have their own food and ethnobotanical traditions. This guide separates edible Rhus species from poison sumac, reviews modern human metabolic research, and covers identification, preparation and safety. 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...