View source for Symphytum

{{Short description|Genus of flowering plants in the borage family Boraginaceae}}
{{About|the genus of plants known as comfrey|the place|Comfrey, Minnesota}}
{{Automatic taxobox
|image=Symphytum caucasicum - Curtis.jpg
|image_caption=''[[Symphytum caucasicum]]''
|taxon=Symphytum
|authority= [[Tourn.]] ex [[Carl Linnaeus|L.]] (1753)
|type_species=''[[Symphytum officinale]]''
|type_species_authority=L.
|subdivision_ranks=Species
|subdivision=27; see text
|subdivision_ref = <ref name = powo>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30124711-2 ''Symphytum'' Tourn. ex L.] ''[[Plants of the World Online]]''. Retrieved 31 July 2024.</ref>
|synonyms =
*''Consolida'' {{small|Riv. ex Ruppius (1745), not validly publ.}}
*''Procopiania'' {{small|Guşul. (1928)}}
*''× Procopiphytum'' {{small|Pawł. (1971)}}
|synonyms_ref = <ref name = powo/>
}}

'''''Symphytum''''' is a [[genus]] of flowering plants in the borage family, [[Boraginaceae]], known by the common name '''comfrey''' (pronounced {{IPAc-en|"|k|V|m|f|r|i}}, from the Latin ''confervere'' to 'heal' or literally to 'boil together', referring to uses in ancient [[traditional medicine]]).

''Symphytum'' is native to northern temperate regions of Europe and Asia, with a wide introduced distribution on both continents as well as the Americas.<ref name = powo/><ref name=WFO/> There are 59 recognized species.<ref name="WFO">{{cite web|publisher=The World Flora Online|date=18 July 2023|title= ''Symphytum'' L.|url= http://www.worldfloraonline.org/taxon/wfo-4000037231|access-date=15 June 2024}}</ref> More than 150 species have been cataloged by botanists.<ref>{{Cite web |title=International Plant Names Index |url=https://www.ipni.org/search?page=4&q=symphytum |access-date=2025-07-01 |website=www.ipni.org}}</ref> Some species and [[Hybrid plant|hybrids]], particularly ''[[Symphytum officinale|S. officinale]]'', ''[[Symphytum grandiflorum]]'', and [[Symphytum × uplandicum|''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.<ref name="usda">{{PLANTS |id=CYVI |taxon=Cynoglossum virginianum |access-date=2018-11-20}}</ref>

==Species==
27 species are accepted.<ref name = powo/>
*''[[Symphytum aintabicum]]'' {{small|Hub.-Mor. & Wickens}}
*''[[Symphytum anatolicum]]'' {{small|Boiss.}}
*''[[Symphytum asperum]]'' {{small|Lepech.}} – prickly comfrey, rough comfrey
*''[[Symphytum × bicknellii]]'' {{small|Buckn.}}
*''[[Symphytum bornmuelleri]]'' {{small|Buckn.}}
*''[[Symphytum brachycalyx]]'' {{small|Boiss.}} – Palestine comfrey
*''[[Symphytum bulbosum]]'' – bulbous comfrey
*''[[Symphytum carpaticum]]'' {{small|Yu.M.Frolov}}
*''[[Symphytum caucasicum]]'' – Caucasian comfrey
*''[[Symphytum circinale]]'' {{small|Runemark}}
*''[[Symphytum cordatum]]'' {{small|Waldst. & Kit. ex Willd.}}
*''[[Symphytum creticum]]'' {{small|(Willd.) Runemark}}
*''[[Symphytum davisii]]'' {{small|Wickens}}
*''[[Symphytum × ferrariense]]'' {{small|C.Massal.}}
*''[[Symphytum grandiflorum]]'' {{small|DC.}} – creeping comfrey
*''[[Symphytum gussonei]]'' {{small|F.W.Schultz}}
*''[[Symphytum hajastanum]]'' {{small|Gvin.}}
*''[[Symphytum ibiricum]]'' {{small|Steven}} – Iberian comfrey<ref>{{cite web |title=Symphytum ibericum |url=https://www.rhs.org.uk/plants/details?plantid=1894 |publisher=rhs.org.uk |access-date=23 April 2017}}</ref>
*''[[Symphytum kurdicum]]'' {{small|Boiss. & Hausskn.}}
*''[[Symphytum longisetum]]'' {{small|Hub.-Mor. & Wickens}}
*''[[Symphytum × mosquense]]'' {{small|S.R.Majorov & D.D.Sokoloff}}
*''[[Symphytum officinale]]'' {{small|L.}} – comfrey
*''[[Symphytum orientale]]'' {{small|L.}} – white comfrey
*''[[Symphytum ottomanum]]'' {{small|Friv.}}
*''[[Symphytum podcumicum]]'' {{small|Yu.M.Frolov}}
*''[[Symphytum pseudobulbosum]]'' {{small|Azn.}}
*''[[Symphytum savvalense]]'' {{small|Kurtto}}
*''[[Symphytum sylvaticum]]'' {{small|Boiss.}}
*''[[Symphytum tauricum]]'' {{small|Willd.}} – Crimean comfrey
*''[[Symphytum tuberosum]]'' {{small|L.}} – tuberous comfrey
*''[[Symphytum × ullepitschii]]'' {{small|Wettst.}}
*''[[Symphytum × uplandicum]]'' {{small|Nyman}} (''S. asperum'' × ''S. officinale'', synonym: ''S. peregrinum'') – Russian comfrey, healing herb, blackwort, bruisewort, wallwort, gum plant
[[File:Symphytum uplandicum x Bocking 14.jpg|thumb|Russian comfrey (''Symphytum × uplandicum'')]]
[[File:Russian comfrey close 800.jpg|180px|thumb|Flowers of Russian comfrey]]
*''[[Symphytum × wettsteinii]]'' {{small|Sennholz}}

==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]] (the [[organic gardening]] organization itself named after [[Henry Doubleday (horticulturalist)|Henry Doubleday]], who first introduced Russian comfrey into Britain in the nineteenth century) following trials at [[Bocking, Essex]].<ref>{{Cite book |last=Hills |first=Lawrence Donegan |title=Fighting like the flowers: an autobiography |date=1989 |publisher=Green Books |isbn=978-1-870098-30-4 |location=Ford House}}</ref>

===Propagation===
{{more citations needed|section|date=May 2018}}

Bocking 4 and 14 are sterile, and therefore will not set seed (one of its advantages over other cultivars as it will not spread out of control); thus, it is propagated from [[root cutting]]s. The gardener can produce "offsets" from mature, strongly growing plants by driving a spade horizontally through the leaf clumps about {{cvt|7|cm}} 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.<ref name="teynor">{{cite web |vauthors=Teynor TM, Putnam DH, Doll JD, Kelling KA, Oelke EA, Undersander DJ, Oplinger ES|title=Comfrey |url=https://www.hort.purdue.edu/newcrop/afcm/comfrey.html |work=Alternative Field Crops Manual |publisher=University of Wisconsin, Extension, Cooperative-Extension|date=February 1992 |access-date=25 March 2014}}</ref>


==Phytochemistry, folk medicine, and toxicity==
[[Traditional medicine|Folk medicine]] 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<ref name=HyamPank95p486>{{Cite book |last1=Hyam |first1=R. |last2=Pankhurst |first2=R.J. |year=1995 |title=Plants and their names : a concise dictionary |publication-place=Oxford |publisher=Oxford University Press |isbn=978-0-19-866189-4 |name-list-style=amp |page=486}}</ref>{{source needed|reason=Again, this etymological explanation is incorrect. There is a word σύμφυσις (growing together, natural junction, esp. of the bones) and there is a word σύμφυτος/ον (e.g. 'grown together'), but not *σύμφυτις. And *σύμφυτις and φυτόν would yield 'symphytiphyton'. And σύμφυτον is the ancient Greek naam for this plant. Please, use a reliable source.|date=April 2025}}, referring to its ancient uses. Similarly, the common French name is {{Lang|fr|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 [[phytochemical]]s in varying amounts, including [[allantoin]], [[mucilage]], [[saponin]]s, [[tannin]]s, [[pyrrolizidine alkaloid]]s, and [[inulin]], among others.<ref name="drugs">{{cite web |title=Comfrey |url=https://www.drugs.com/npp/comfrey.html |publisher=Drugs.com |access-date=22 May 2018 |date=17 July 2017}}</ref> Pyrrolizidine alkaloids are responsible for comfrey's [[hepatotoxicity|liver toxicity]],<ref>{{cite journal |last1=Mei |first1=Nan |last2=Guo |first2=Lei |last3=Fu |first3=Peter P. |last4=Fuscoe |first4=James C. |last5=Luan |first5=Yang |last6=Chen |first6=Tao |title=Metabolism, genotoxicity, and carcinogenicity of Comfrey |journal=Journal of Toxicology and Environmental Health Part B: Critical Reviews |date=October 2010 |volume=13 |issue=7–8 |pages=509–526 |doi=10.1080/10937404.2010.509013 |pmid=21170807 |pmc=5894094|bibcode=2010JTEHB..13..509M }}</ref> which is associated with consuming this plant or its [[extract]]s.<ref name="drugs" /> In modern [[herbalism]], comfrey is most commonly used [[Topical medication|topically]].<ref name="drugs" /><ref>{{cite journal |last1=Grant |first1=G |last2=Nolan |first2=M |last3=Ellis |first3=N |title=A reappraisal of the Malaise Inventory. |journal=Social Psychiatry and Psychiatric Epidemiology |date=July 1990 |volume=25 |issue=4 |pages=170–8 |doi=10.1007/BF00782957 |pmid=2399473 |pmc=2399473}}</ref><ref>{{cite journal |last1=Miller |first1=Lucinda G. |title=Herbal Medicinals: Selected Clinical Considerations Focusing on Known or Potential Drug-Herb Interactions |journal=Archives of Internal Medicine |date=9 November 1998 |volume=158 |issue=20 |pages=2200–2211 |doi=10.1001/archinte.158.20.2200 |pmid=9818800 |doi-access=}}</ref>

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.<ref>{{cite web |url=https://www.fda.gov/Food/RecallsOutbreaksEmergencies/SafetyAlertsAdvisories/ucm111219.htm |archive-url=https://wayback.archive-it.org/7993/20171114115012/https://www.fda.gov/Food/RecallsOutbreaksEmergencies/SafetyAlertsAdvisories/ucm111219.htm |url-status=dead |archive-date=2017-11-14 |title=FDA/CFSAN – FDA Advises Dietary Supplement Manufacturers to Remove Comfrey Products From the Market (archived copy) |website=[[Food and Drug Administration]] |access-date=2023-06-12 }}</ref> Use of comfrey is particularly discouraged during pregnancy and lactation, in infants, and in people with liver, kidney, or [[vascular disease|vascular]] diseases.<ref name="drugs" /><ref>{{cite journal |last1=Yeong |first1=Mee Ling |last2=Swinburn |first2=Boyd |last3=Kennedy |first3=Mark |last4=Nicholson |first4=Gordon |title=Hepatic veno-occlusive disease associated with comfrey ingestion |journal=Journal of Gastroenterology and Hepatology |date=March 1990 |volume=5 |issue=2 |pages=211–214 |doi=10.1111/j.1440-1746.1990.tb01827.x |pmid=2103401 |s2cid=42511497}}</ref>

==References==
{{Reflist}}

{{Taxonbar|from=Q161566}}
{{Authority control}}

[[Category:Symphytum| ]]
[[Category:Boraginaceae genera]]
[[Category:Botanical taxa named by Carl Linnaeus]]