Symphytum


Symphytum is a genus of flowering plants in the borage family, Boraginaceae, known by the common name comfrey.
Symphytum is native to northern temperate regions of Europe and Asia, with a wide introduced distribution on both continents as well as the Americas. There are 59 recognized species. More than 150 species have been cataloged by botanists. Some species and hybrids, particularly S. officinale, Symphytum grandiflorum, and S. × uplandicum, are used in gardening and herbal medicine. Species in the genus Symphytum are different from Andersonglossum virginianum, known as wild comfrey, which is another member of the borage family.

Species

27 species are accepted.
  • Symphytum aintabicum
  • Symphytum anatolicum
  • Symphytum asperum – prickly comfrey, rough comfrey
  • Symphytum × bicknellii
  • Symphytum bornmuelleri
  • Symphytum brachycalyx – Palestine comfrey
  • Symphytum bulbosum – bulbous comfrey
  • Symphytum carpaticum
  • Symphytum caucasicum – Caucasian comfrey
  • Symphytum circinale
  • Symphytum cordatum
  • Symphytum creticum
  • Symphytum davisii
  • Symphytum × ferrariense
  • Symphytum grandiflorum – creeping comfrey
  • Symphytum gussonei
  • Symphytum hajastanum
  • Symphytum ibiricum – Iberian comfrey
  • Symphytum kurdicum
  • Symphytum longisetum
  • Symphytum × mosquense
  • Symphytum officinale – comfrey
  • Symphytum orientale – white comfrey
  • Symphytum ottomanum
  • Symphytum podcumicum
  • Symphytum pseudobulbosum
  • Symphytum savvalense
  • Symphytum sylvaticum
  • Symphytum tauricum – Crimean comfrey
  • Symphytum tuberosum – tuberous comfrey
  • Symphytum × ullepitschii
  • Symphytum × uplandicum – Russian comfrey, healing herb, blackwort, bruisewort, wallwort, gum plant
  • ''Symphytum × wettsteinii''

    Cultivation

The Russian comfrey 'Bocking 4' and 'Bocking 14' cultivars were developed during the 1950s by Lawrence D. Hills, the founder of the Henry Doubleday Research Association following trials at Bocking, Essex.

Propagation

Bocking 4 and 14 are sterile, and therefore will not set seed ; thus, it is propagated from root cuttings. The gardener can produce "offsets" from mature, strongly growing plants by driving a spade horizontally through the leaf clumps about below the soil surface. This removes the crown, which can then be split into pieces. The original plant will quickly recover, and each piece can be replanted with the growing points just below the soil surface, and will quickly grow into new plants. Offsets can also be purchased by mail order from specialist nurseries in order to initially build up a stock of plants.

Phytochemistry, folk medicine, and toxicity

names for comfrey include knitbone, boneset, and the derivation of its Latin name Symphytum (from the Greek symphytis, 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, and inulin, among others. Pyrrolizidine alkaloids are responsible for comfrey's liver toxicity, which is associated with consuming this plant or its extracts. In modern herbalism, comfrey is most commonly used topically.
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. Use of comfrey is particularly discouraged during pregnancy and lactation, in infants, and in people with liver, kidney, or vascular diseases.