comfrey

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comfrey

(kŭm′frē)
n. pl. com·freys
Any of various hairy perennial Eurasian herbs of the genus Symphytum, especially S. officinale, having variously colored flowers in coiled cymes and long used in herbal medicine.

comfrey

Herbal medicine
A perennial herb, the leaves and roots of which contain allantoin, carotene, essential oil, glycosides, mucilage, resin, saponins, tannins, triterpenoids, vitamin B12 and zinc. Comfrey is a medicinal herb staple, promoting the growth of bone and connective tissue, and breaks down red blood cells (hence its popular name, bruisewort). It is anti-inflammatory, and has been used internally for haemorrhage, diarrhoea, gastric ulcers, colitis, bronchitis, whooping cough, and other respiratory tract infections; it is used topically for burns, bruises, sprains, boils, sore breasts, ulcers, gangrene, haemorrhoids and varicose veins.
 
Toxic effects
Liver tumours may develop in lab rats when exposed to high levels; it is a potential carcinogen.