The Common Comfrey (Symphytum officinale family: Boraginaceae), also called Blackwort, Healing Herb, Bruiswort, Salsify, Slippery Root, and Knitbone, is a hardy plant which can grow to a height of 4 ft. Native to Eurasia and naturalized in North America, it grows in moist damp areas.
This herb develops flowers and has a thick, externally black root, and relatively large leaves. Forked clusters of purplish, pinkish, or yellow-white nodding flowers are arranged in crowded terminal cymes and appear in early summer to early fall. Suitable for herb gardens, meadows and informal parts of the garden.
Comfrey is, however, an important feed in some parts of the world. It is also grown as an organic compost and mulch. Every garden should have a patch of comfrey. It is an invaluable crop for and organic gardener, as the leaves, when regularly cut, are an activator for the compost heap as well as being a valuable source of potassium and phosphate.3
Both Leaf and Root have been used medicinally. Topically, comfrey preparations are used in the treatment of bruises, sprains and distortions, as well as painful conditions affecting muscles and joints.2 Probably nature’s most famous wound-healing species, comfrey contains at least eight pyrrolizidine alkaloids, which have been shown to cause liver toxicity and liver cancer in rats. Ingestion of a tea prepared from comfrey roots is especially dangerous as the roots contain much higher concentrations of the pyrrolizidine alkaloids than leaves and stems of the plant.1
- Gail B. Mahady, Harry H.S. Fong, N.R. Farnsworth – Botanical Dietary Supplements: Quality, Safety and Efficacy
- Susan G. Wynn, Barbara Fougère – Veterinary Herbal Medicine
- Nick Hamilton – Grow Organic: Fruit and Vegetables Fresh from Your Garden