Editing Goldenseal

{{Short description|Species of flowering plant}}
{{For|the magazine from West Virginia|Goldenseal (magazine)}}
{{Redirect|Orangeroot||Orange-root}}
{{Speciesbox
|name = Goldenseal
|status = VU
|status_system = IUCN3.1
|status_ref = <ref name=iucn>{{cite journal |author=Oliver, L. |title=''Hydrastis canadensis'' |journal=[[The IUCN Red List of Threatened Species]] |volume=208 |at=e.T44340011A44340071 |publisher=[[IUCN]] |year=2016 |doi=10.2305/IUCN.UK.2017-2.RLTS.T44340011A44340071.en |doi-access=free }}</ref>
| status2 = CITES_A2
| status2_system = CITES
|image = Hydrastis_canadensis.jpg
|image_caption=''Hydrastis canadensis''
|display_parents = 3
|grandparent_authority= [[Constantine Samuel Rafinesque|Rafinesque]], 1815
|genus = Hydrastis
|parent_authority= [[Carl Linnaeus|L.]]
|species = canadensis
|authority = [[Carl Linnaeus|L.]]
}}

'''Goldenseal''' ('''''Hydrastis canadensis'''''), also called '''orangeroot'''<ref name=GRIN>{{GRIN | access-date = 2017-12-12}}</ref> or '''yellow puccoon''',<ref name=GRIN/> is a [[perennial plant|perennial]] [[herb]] in the [[buttercup]] family [[Ranunculaceae]], native to North America. It may be distinguished by its thick, yellow knotted [[rootstock]]. The stem is purplish and hairy above ground and yellow below ground where it connects to the yellow [[rhizome]]. Goldenseal reproduces both clonally through the rhizome<ref name=":5">{{Cite journal|last1=Christensen|first1=Deanna|last2=Gorchov|first2=David|date=2010|title=Population dynamics of goldenseal (Hydrastis canadensis) in the core of its historical range|journal=Plant Ecology|volume=210|issue=2|pages=195–211|doi=10.1007/s11258-010-9749-2|bibcode=2010PlEco.210..195C |s2cid=8956947}}</ref> and sexually, with clonal division more frequent than asexual reproduction. It takes between 4 and 5 years for a plant to reach sexual maturity, i.e. the point at which it produces flowers. Plants in the first stage, when the seed erupts and cotyledons emerge, can remain in this state one or more years. The second vegetative stage occurs during years two and three (and sometimes longer) and is characterized by the development of a single leaf and absence of a well developed stem. Finally, the third stage is reproductive, at which point flowering and fruiting occurs. This last stage takes between 4 and 5 years to develop.<ref>{{Cite web|work=NatureServe Explorer 2.0|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.154701/Hydrastis_canadensis|last= Oliver | first= L. | date=2013|access-date=2023-01-18|title=Hydrastis canadensis — Goldenseal}}</ref>

A second species from [[Japan]], previously listed as ''Hydrastis palmatum'', is now usually classified in another [[genus]], as ''[[Glaucidium (plant)|Glaucidium palmatum]]''.

==Description==

''Hydrastis canadensis'' is a [[herbaceous]] [[perennial]] growing from a horizontal, yellowish [[rhizome]] that is thick with knobby knots. The finely hairy, upright, unbranched, stems grow to {{Convert|15–50|cm|abbr=off|frac=2}} tall.<ref name="FNA">{{Cite web|title=Hydrastis canadensis in Flora of North America @ efloras.org|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220006616|access-date=2021-01-16|website=www.efloras.org}}</ref> Fertile plants have a single stem with two palmately lobed [[leaves]].<ref name="CoffinPfannmuller1988">{{cite book|author1=Barbara Coffin|author2=Lee Pfannmuller|title=Minnesota's Endangered Flora and Fauna|url=https://books.google.com/books?id=wfWNq91AjeoC|year=1988|publisher=U of Minnesota Press|isbn=978-0-8166-1689-3|page=101}}</ref> Flowering plants produce a single terminal flower with no petals and three [[sepal]]s and 12 or more conspicuous white [[pistil]]s; flowering occurs for a short time in spring.<ref name="CoffinPfannmuller1988"/> Fertilized flowers grow into red, raspberry-like fruits with one or two seeds.<ref name="CoffinPfannmuller1988"/>

{{gallery|mode=packed
|Hydrastis.jpg|Goldenseal in flower
|Goldenseal (cropped).jpg|Goldenseal in fruit
}}

=== Constituents and modern pharmacology ===
Goldenseal contains the isoquinoline alkaloids [[hydrastine]], [[berberine]], berberastine, [[hydrastinine]], tetrahydroberberastine, [[canadine]] and canalidine.<ref>{{Cite journal |vauthors=Weber HA, Zart MK, Hodges AE, etal |date=December 2003 |title=Chemical comparison of goldenseal (Hydrastis canadensis L.) root powder from three commercial suppliers |journal=Journal of Agricultural and Food Chemistry |volume=51 |issue=25 |pages=7352–8 |doi=10.1021/jf034339r |pmid=14640583}}</ref> A related compound, 8-oxotetrahydrothalifendine, was identified in one study.<ref>{{Cite journal |vauthors=Gentry EJ, Jampani HB, Keshavarz-Shokri A, etal |date=October 1998 |title=Antitubercular natural products: berberine from the roots of commercial Hydrastis canadensis powder. Isolation of inactive 8-oxotetrahydrothalifendine, canadine, beta-hydrastine, and two new quinic acid esters, hycandinic acid esters-1 and −2 |journal=Journal of Natural Products |volume=61 |issue=10 |pages=1187–93 |doi=10.1021/np9701889 |pmid=9784149}}</ref> The ''[[United States Pharmacopeia|United States Pharmacopoeia]]'' requires goldenseal sold as a supplement to have hydrastine concentrations of at least 2% and berberine concentrations of at least 2.5%.<ref name=":4">{{Cite journal |last1=Douglas |first1=JA |last2=Follett |first2=JM |last3=Waller |first3=JE |last4=Sansom |first4=CE |date=2010 |title=Seasonal variation of biomass and bioactive alkaloid content of goldenseal, Hydrastis canadensis |journal=Fitoterapia |volume=81 |issue=7 |pages=925–928 |doi=10.1016/j.fitote.2010.06.006 |pmid=20550958}}</ref> The requirements in Europe are that hydrastine concentrations be at least 2.5% and that berberine concentrations at least 3%.<ref name=":4" /> The hydrastine concentrations of goldenseal plants range between 1.5% and 5%, while the berberine concentrations are usually between 0.5% and 4.5%.<ref name=":3">{{Cite journal |last1=Mahady |first1=Gail |last2=Chadwick |first2=Lucas |date=2001 |title=Goldenseal (Hydrastis canadensis): Is there enough scientific evidence to support safety and efficacy? |journal=Nutrition in Clinical Care |volume=4 |issue=5 |pages=243–249 |doi=10.1046/j.1523-5408.2001.00004.x}}</ref> Goldenseal is harvested for its rhizomes because the concentrations of hydrastine and berberine in the shoots do not meet these requirements.<ref name=":4" /> Berberine and hydrastine act as quaternary bases and are poorly soluble in water but freely soluble in alcohol. The herb seems to have synergistic antibacterial activity over berberine ''[[in vitro]]'', possibly as a result of [[efflux pump]] inhibitory activity.<ref>Ettefagh K.A., Burns J.T., Junio H.A., Kaatz G.W., Cech N.B., "Goldenseal (Hydrastis canadensis L.) Extracts Synergistically Enhance the Antibacterial Activity of Berberine via Efflux Pump Inhibition", ''Planta Medica'' 2010</ref>

==Distribution and habitat==
Found in southeastern [[Canada]] and the eastern [[United States]], the plant grows in mesic forests under [[deciduous]] trees.<ref name="CoffinPfannmuller1988" /> It is found in sheltered ravines or on talus slopes. It seems to be intolerant of disturbances in the tree canopy and grazing.<ref name="CoffinPfannmuller1988" /> It can be found growing in association with other uncommon plants such as ''[[Jeffersonia diphylla]]'' (twinleaf) and ''[[Dicentra canadensis]]'' (squirrel corn).<ref name="CoffinPfannmuller1988" />

==Conservation==

Goldenseal became popular in the mid-19th century. By 1905, the herb was much less plentiful because of overharvesting and habitat destruction. Roots of goldenseal are listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora ([[CITES]]),<ref>Foster Steven and Tyler Varro E. (1999): Tyler's Honest Herbal: A sensible guide to the use of herbs and related remedies. Binghamton, NY, The Haworth Herbal Press</ref> meaning a CITES permit to export is required. The [[U.S. Fish and Wildlife Service]] recommends that diggers and harvesters track sales and harvests and prove legality of all harvests.<ref name=":0">Robbins, C.S., 2000. Comparative analysis of management regimes and medicinal plant trade monitoring mechanisms for American ginseng and goldenseal. ''Conservation Biology'', ''14''(5), pp.1422–1434.</ref>

Canada, as well as 17 of the 27 U.S. states where goldenseal grows natively, have declared it as threatened, vulnerable or uncommon.<ref name=":0" /><ref>{{Cite web |title=United Plant Savers, Goldenseal |url=http://www.unitedplantsavers.org/goldenseal-hydrastis-canadensis |website=Unitedplantsavers.org|date=2 August 2019 }}</ref> More than 60 million goldenseal plants are picked each year without being replaced.<ref>{{Cite news |last=Dworkin |first=Norine |year=1999 |title=Where Have All the Flowers Gone? – herbal supplements threaten some herb species |work=Vegetarian Times |url=http://findarticles.com/p/articles/mi_m0820/is_1999_Sept/ai_55512105}}</ref> Although goldenseal's geographical range is wide, it is found in small quantities in these habitats.<ref name=":5" /> The core of the herb's range is in the [[Ohio River|Ohio River Valley]],<ref name=":5" /> but its population there has decreased by almost half.<ref>{{Cite journal |last1=Mulligan |first1=Margaret |last2=Gorchov |first2=David |date=2004 |title=Population loss of goldenseal, Hydrastis canadensis L. (Ranunculaceae) in Ohio |url=http://rave.ohiolink.edu/etdc/view?acc_num=miami1066347702 |journal=Journal of the Torrey Botanical Society |volume=131 |issue=4 |pages=305–310 |doi=10.2307/4126936 |jstor=4126936}}</ref> The process of [[mountain top removal]] mining has recently put the wild goldenseal population at major risk from loss of habitat.<ref>{{Cite periodical|title= Saving Wild Ginseng, Goldenseal, and other Native Plants from Mountain Top Removal|url=http://cms.herbalgram.org/herbalgram/issue73/article3080.html|access-date=2023-01-18|magazine=HerbalGram | author1=Dean Myles| date= 2007|issue= 73|page=50 |publisher=American Botanical Council  }}</ref>

Many [[herbalist]]s urge caution in choosing products containing goldenseal, as they may have been harvested in an [[sustainability|unsustainable]] manner rather than having been [[organic farming|organically cultivated]].{{citation needed|date=May 2013}}

There are several berberine-containing plants that can serve as useful alternatives, including [[Chinese coptis]], [[Xanthorhiza|yellowroot]] or [[Oregon grape]] root.<ref>Bergner, Paul. ''The Healing Powers of Echinacea, Goldenseal and Other Immune System Herbs''. Prima 1997 {{ISBN|978-0-7615-0809-0}}</ref>

==Toxicity==
According to the [[American Cancer Society]], "Goldenseal can have toxic side effects, and high doses can cause death."<ref name="cancer">{{Cite web|date=2008|author1=((American Cancer Society))|title=Goldenseal|url=http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/herbsvitaminsandminerals/goldenseal|access-date=2023-01-18|archive-url=https://web.archive.org/web/20150127215214/http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/herbsvitaminsandminerals/goldenseal |archive-date=2015-01-27 }}</ref>

Side effects of goldenseal may include "digestive complaints, nervousness, depression, constipation, rapid heartbeat, diarrhea, stomach cramps and pain, mouth ulcers, nausea, seizures, vomiting, and [[central nervous system depression]]. High doses may cause breathing problems, paralysis, and even death. Long-term use may lead to vitamin B deficiency, hallucinations, and delirium."<ref name="cancer" /> In addition, goldenseal may cause brain damage to newborn babies if given directly or if taken by breastfeeding or pregnant mothers,<ref name="webmd">[http://www.webmd.com/vitamins-supplements/ingredientmono-943-GOLDENSEAL.aspx?activeIngredientId=943&activeIngredientName=GOLDENSEAL Goldenseal], WebMD.</ref> and may affect blood pressure unpredictably because it contains several compounds that have opposite effects on blood pressure.<ref name="cancer" />

Taking goldenseal over a long period of time can reduce absorption of B vitamins, and it is cautioned to avoid goldenseal during pregnancy and lactation, with gastrointestinal inflammation and with pro-inflammatory disorders.<ref name="autogenerated4">{{cite journal |year=2006 |title=Drugs and Lactation Database (LactMed) |url=https://healthdata.gov/dataset/drugs-and-lactation-database-lactmed |pmid=30000926 |website=Drugs and Lactation Database (LactMed)}}</ref> A 2011 study found rats fed goldenseal constantly for two years had a greater tendency to develop tumors.<ref>Dunnick JK, "Investigating the Potential for Toxicity from Long-Term Use of the Herbal Products, Goldenseal and Milk Thistle."  ''Toxicol Pathol''. 2011 Feb 7;</ref>

Goldenseal has been found to have inhibited [[cytochrome P450]] [[CYP2D6]], [[CYP3A4]] and [[CYP3A5]] activity by approximately 40%, a statistically and clinically significant reduction.<ref>{{cite journal |vauthors=Gurley BJ, Gardner SF, Hubbard MA, Williams DK, Gentry WB, Khan IA, Shah A |year=2005 |title=In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes |journal=Clin. Pharmacol. Ther. |volume=77 |issue=5 |pages=415–26 |doi=10.1016/j.clpt.2005.01.009 |pmc=1894911 |pmid=15900287}}</ref> CYP2D6 is a known metabolizer of many commonly used pharmaceuticals, such as [[antidepressant]]s (including all [[SSRI]]s except for [[fluvoxamine]]), [[neuroleptic]]s, [[codeine]],<ref>{{cite web |title=Interaktion mellan läkemedel - FASS Vårdpersonal |url=https://www.fass.se/LIF/menydokument?userType=0&menyrubrikId=126 |access-date=16 March 2019 |website=Fass.se}}</ref> and [[Metformin]].<ref>{{cite journal |last1=Nguyen |first1=James T. |last2=Tian |first2=Dan-Dan |last3=Tanna |first3=Rakshit S. |last4=Hadi |first4=Deena L. |last5=Bansal |first5=Sumit |last6=Calamia |first6=Justina C. |last7=Arian |first7=Christopher M. |last8=Shireman |first8=Laura M. |last9=Molnár |first9=Bálint |last10=Horváth |first10=Miklós |last11=Kellogg |first11=Joshua J. |year=2021 |title=Assessing Transporter-Mediated Natural Product-Drug Interactions Via In vitro-In Vivo Extrapolation: Clinical Evaluation With a Probe Cocktail |journal=Clinical Pharmacology & Therapeutics |volume=109 |issue=5 |pages=1342–1352 |doi=10.1002/cpt.2107 |pmc=8058163 |pmid=33174626 |last12=Layton |first12=Matthew E. |last13=White |first13=John R. |last14=Cech |first14=Nadja B. |last15=Boyce |first15=Richard D. |last16=Unadkat |first16=Jashvant D. |last17=Thummel |first17=Kenneth E. |last18=Paine |first18=Mary F.}}</ref> Combining goldenseal with such medications should be done with caution and under the supervision of a doctor as it can lead to serious, perhaps fatal, toxicity.<ref>{{cite journal |last1=Zackrisson |first1=A.L. |last2=Holmgren |first2=P. |last3=Gladh |first3=A.B. |last4=Ahlner |first4=J. |last5=Lindblom |first5=B. |date=October 2004 |title=Fatal intoxication cases: cytochrome P 450 2D6 and 2C19 genotype distributions |journal=European Journal of Clinical Pharmacology |publisher=[[Springer-Verlag]] |volume=60 |issue=8 |pages=547–552 |doi=10.1007/s00228-004-0800-x |issn=1432-1041 |pmid=15349706 |s2cid=31679017}}</ref> Those with a genetic deficiency in these enzymes are at particular risk.

== Cultivation ==
As of 1998, only 2.4% of goldenseal plant material originated from a cultivated source rather than wild harvest, although that number was projected to rise by 15–30% over the next several years.<ref name=":0" /> In response to conservation concerns, research has expanded regarding the propagation success of wild plant material for commercial yield. Because goldenseal grows in patches of interconnected ramets reproducing asexually through clonal propagation, transplanting rhizome propagules into cultivated settings is possible.<ref>Predny, M.L. and Chamberlain, J.L., 2005. Goldenseal (Hydrastis canadensis): an annotated bibliography. ''Gen. Tech. Rep. SRS-88. Asheville, NC: US Department of Agriculture, Forest Service, Southern Research Station. 67 p.'', ''88''.</ref><ref>Van der Voort, M.E., Bailey, B., Samuel, D.E. and McGRAW, J.B., 2003. Recovery of populations of goldenseal (Hydrastis canadensis L.) and American ginseng (Panax quinquefolius L.) following harvest. ''The American Midland Naturalist'', ''149''(2), pp.282–292.</ref><ref name=":6">Albrecht, M.A. and McCarthy, B.C., 2006. Comparative analysis of goldenseal (Hydrastis canadensis L.) population re-growth following human harvest: implications for conservation. ''The American midland naturalist'', ''156''(2), pp.229–236.</ref> Seed propagation is also feasible and has advantages such as lower cost and greater genetic variability, but is considered difficult and unpredictable.<ref name=":1">{{cite journal|author=Davis, Jeanine M.|title=Forest Production of Goldenseal|date=1999|journal=Agroforestry Notes (USDA-NAC)|volume=15|url=http://digitalcommons.unl.edu/agroforestnotes/15}}</ref><ref name=":2">Burkhart, E.P. and Jacobson, M.G., 2009. Transitioning from wild collection to forest cultivation of indigenous medicinal forest plants in eastern North America is constrained by lack of profitability. ''Agroforestry systems'', ''76''(2), pp.437–453.</ref>

Goldenseal may be commercially cultivated through agroforestry in natural settings mirroring the plant's ecological environment, or on farms with artificial shade canopies.<ref name=":2" /><ref name=":1" /> Another propagation method of goldenseal utilizes a controlled environment such as a greenhouse growing lab where the plant's environmental needs such as light, water and temperature are artificially simulated. Crop selection and biotechnology experimentation may be employed to increase yield and pharmacological potency.<ref>Canter, P.H., Thomas, H. and Ernst, E., 2005. Bringing medicinal plants into cultivation: opportunities and challenges for biotechnology. ''TRENDS in Biotechnology'', ''23''(4), pp.180–185.</ref> Controlled environments can greatly reduce the amount of time required to grow goldenseal to its desired harvestable state. While forest-cultivated plants double in mass every three to five years, plants can double in mass every 15 weeks in growth chambers and triple in growth when in a course soil medium.<ref>Adelberg, J., Salido, A., Kelly, R.M. and Beavers, R., 2016. Rapid Growth of High Quality Goldenseal Plants in Controlled Environment Growth Chambers. In ''Medicinal and Aromatic Crops: Production, Phytochemistry, and Utilization''(pp. 65–74). American Chemical Society.</ref> Subculturing can take place every 30 days to mass-propagate the plant.<ref>Bedir, E., Lata, H., Schaneberg, B., Khan, I.A. and Moraes, R.M., 2003. Micropropagation of Hydrastis canadensis: Goldenseal a North American endangered species. ''Planta medica'', ''69''(01), pp.86–88.</ref>

Another option is cultivating goldenseal in new regions. An experiment conducted by Douglas et al.<ref name=":9">{{Cite journal|last1=Douglas|first1=JA|last2=Follett|first2=JM|last3=Waller|first3=JE|last4=Sansom|first4=CE|date=2013|title=Root and rhizome production of goldenseal (Hydrastis canadensis L.) under cultivated conditions in New Zealand|journal=New Zealand Journal of Crop & Horticultural Science|volume=41|issue=1 |pages=32–40|doi=10.1080/01140671.2012.743467|bibcode=2013NZJCH..41...32D |s2cid=85014533}}</ref> grew goldenseal over a six-year period in a warm, temperate environment in New Zealand. The yields were 74% higher in the sixth year of growth compared to the fourth year of growth, which is when goldenseal is normally harvested.<ref name=":9" /> The overall growth of the allochthonous goldenseal was comparable to that found in the United States, and the hydrastine and berberine concentrations were within the American and European standards.<ref name=":9" /> Cultivating goldenseal in a New Zealand environment that is similar to its home range is an option to maintain its population.<ref name=":9" />

=== Research on harvest effects ===
Research completed by Albrecht and McCarthy<ref name=":6" /> shows that when goldenseal is harvested in the fall season, it has a faster population recovery than with midsummer harvests. However, a study by Douglas et al.<ref name=":4" /> showed that goldenseal has the highest concentrations of hydrastine and berberine in the early summer. Their research also showed that three to five years of growth will yield the highest concentration of alkaloids in the plant.<ref name=":4" />

Two experiments done by Sinclair and Catling<ref name=":7">{{Cite journal |last1=Sinclair |first1=Adrianne |last2=Catling |first2=Paul |date=2003 |title=Restoration of Hydrastis canadensis by transplanting with disturbance simulation: results of one growing season |journal=Restoration Ecology |volume=11 |issue=2 |pages=217–222 |doi=10.1046/j.1526-100x.2003.00183.x |bibcode=2003ResEc..11..217S |s2cid=84421549}}</ref><ref name=":8">{{Cite journal |last1=Sinclair |first1=Adrianne |last2=Catling |first2=Paul |date=2004 |title=Restoration of Hydrastis canadensis: experimental test of a disturbance hypothesis after two growing seasons |journal=Restoration Ecology |volume=12 |issue=2 |pages=184–189 |doi=10.1111/j.1061-2971.2004.00297.x |bibcode=2004ResEc..12..184S |s2cid=84344771}}</ref> on the effects of soil turnover, fertilization and transplanting of goldenseal show that disturbances actually benefit the growth of goldenseal. The results from the first growing season of the experiment showed that soil turnover and fertilization combined show the greatest increase in plant biomass,<ref name=":7" /> while the results after two growing seasons showed that this group also yielded the highest proportion of flowering plants, fruit production and seed production.<ref name=":8" /> Both experiments also showed that soil disturbances benefit the growth of goldenseal.<ref name=":7" /><ref name=":8" />

== Uses ==

At the time of the [[European colonization of the Americas]], goldenseal was in extensive use among certain [[Native Americans in the United States|Native American tribes of North America]], both as a medicine and as a coloring material. In 1798, [[Benjamin Smith Barton]] referred to the [[Cherokee]] use of goldenseal as a cancer treatment;<ref>{{Cite web |last=Barton |first=Benjamin |title=Benjamin Smith Barton MD – Collections for an Essay Towards a Materia Medica of the United States (p. 8) |url=https://www.nlm.nih.gov/exhibition/georgewashington/digitalgallery/detail-barton-book.html |access-date=2017-02-20 |website=Nlm.nih.gov}}</ref> he called attention to its properties as a bitter tonic, and as a local wash for [[ophthalmia]]. It became a favorite of the [[Eclectic medicine|Eclectics]] from the time of [[Constantine Raffinesque]] in the 1830s. Tribes also used goldenseal for digestive issues, as an eyewash, as a diuretic and as a bitter.<ref name=":3" />

According to the American Cancer Society, "Available scientific evidence does not support claims that goldenseal is effective in treating cancer or other diseases."<ref name="cancer" /> According to the [[National Center for Complementary and Integrative Health]], "The scientific evidence does not support the use of goldenseal for any health-related purpose."<ref name="NCCIH">{{Cite web|title=Goldenseal|url=https://www.nccih.nih.gov/health/goldenseal|access-date=2023-01-18|website=NCCIH|language=en}}</ref>

In the early 20th century, it was used as a yellow dye, astringent, and insect repellent.<ref>{{cite book |last1=Niering |first1=William A. |title=The Audubon Society Field Guide to North American Wildflowers, Eastern Region |last2=Olmstead |first2=Nancy C. |publisher=Knopf |year=1985 |isbn=0-394-50432-1 |page=737 |author-link1=William Niering |orig-year=1979}}</ref>

== See also ==
* [[Coptisine]]
* [[List of ineffective cancer treatments]]

==References==
{{Reflist}}

==Literature==
* {{Cite book| author=Blanchan, Neltje | title=Wild Flowers Worth Knowing | year=2005 | publisher=[[Project Gutenberg|Project Gutenberg Literary Archive Foundation]] | isbn=0-665-98934-2 | author-link=Neltje Blanchan| title-link=Wild Flowers Worth Knowing }}
* John Uri Lloyd (1908). ''Hydrastis canadensis''. Lloyd Library, Cincinnati. [http://www.swsbm.com/ManualsOther/Hydrastis-Lloyd.PDF PDF]
* W. Scott Persons and Jeanine M. Davis (2005) ''Growing & Marketing Ginseng, Goldenseal & Other Woodland Medicinals''  Bright Mountain Books. {{ISBN|978-0-914875-42-0}}
* Richo Cech.  (2002) ''Growing At-Risk Medicinal Herbs, Cultivation, Conservation and Ecology'' {{ISBN|978-0-9700312-1-1}}

==External links==
{{Commons}}
* [http://www.rootreport.frec.vt.edu/docs/GoldensealAnnotatedBibliography.pdf Goldenseal: An Annotated Bibliography]
* [http://altmedicine.about.com/cs/herbsvitaminsek/a/Goldenseal.htm About.com's Herb & Supplement Guide: Goldenseal] {{Webarchive|url=https://web.archive.org/web/20061004213908/http://altmedicine.about.com/cs/herbsvitaminsek/a/Goldenseal.htm |date=2006-10-04 }}
* Bruce A. Ford: [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=115979 ''Hydrastis''] in the ''Flora of North America'', Volume 3

{{Medicinal herbs & fungi}}
{{Taxonbar|from1=Q1051710|from2=Q9005595|from3=Q5905589}}
{{Authority control}}

[[Category:Ranunculaceae]]
[[Category:Plants described in 1759]]
[[Category:Plants used in traditional Native American medicine]]
[[Category:Flora of Northern America]]
[[Category:Plant dyes]]
[[Category:Taxa named by Carl Linnaeus]]
<!-- [[Category:Monotypic plant genera]] moved to Hydratis redirect-->