Symphytum

Species include:

• Symphytum asperum – prickly comfrey, rough comfrey
• Symphytum bulbosum – bulbous comfrey
• Symphytum caucasicum – Caucasian comfrey
• Symphytum ibericum – creeping comfrey, Iberian comfrey[3]
• Symphytum officinale – comfrey
• Symphytum orientale – white comfrey
• Symphytum tauricum – Crimean comfrey
• Symphytum tuberosum – tuberous comfrey
• Symphytum × uplandicum (S. asperum × S. officinale, synonym: S. peregrinum) – Russian comfrey, healing herb, blackwort, bruisewort, wallwort, gum plant

Russian comfrey (Symphytum × uplandicum)

Flowers of Russian comfrey

The Russian comfrey 'Bocking 14' cultivar was developed during the 1950s by Lawrence D Hills, the founder of the Henry Doubleday Research Association (the organic gardening organisation itself named after the Quaker pioneer who first introduced Russian comfrey into Britain in the nineteenth century) following trials at Bocking, near Braintree.

Folk medicine names for comfrey include knitbone, boneset, and the derivation of its Latin name Symphytum (from the Greek symphis, meaning growing together of bones, and phyton, a plant), referring to its ancient uses. Similarly, the common French name is consoude, meaning to weld together. The tradition in different cultures and languages suggest a common belief in its usefulness for mending bones.

Comfrey contains mixed phytochemicals in varying amounts, including allantoin, mucilage, saponins, tannins, pyrrolizidine alkaloids, inulin, and proteins, among others.[5] Liver toxicity is associated with consuming this plant or its extracts.[5] In modern herbalism, comfrey is most commonly used topically.[5][6][7]

In 2001, the United States Food and Drug Administration issued a ban of comfrey products marketed for internal use, and a warning label for those intended for external use.[8][9] Comfrey is particularly contraindicated during pregnancy and lactation, in infants, and in people with liver, kidney, or vascular diseases.[5][10]

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