View source for Eutrochium

{{Short description|Genus of flowering plants}}
{{Automatic taxobox
| name = Joe-Pye weeds
| image = Joe Pye 5426.JPG
| image_caption = Joe-Pye weed in flower
| image2 = Monarch&JoePyeWeed 02.jpg
| display_parents = 2
| taxon = Eutrochium
| authority = [[Constantine Samuel Rafinesque|Raf.]]
| synonyms_ref = <ref>{{Tropicos |access-date=2018-08-26}}</ref>
| synonyms  = *''Eupatoriadelphus'' <small>[[R.M.King]] & [[H.Rob.]]</small>
*''Solidago'' subgenus ''Euthamia'' <small>[[Nutt.]]</small>{{citation needed|date=August 2018}}
*''Eupatorium'' sect. ''Verticillatum'' <small>[[DC.]]</small>
}}

'''''Eutrochium''''' is a North American genus of herbaceous flowering plants in the family [[Asteraceae]]. They are commonly referred to as '''Joe-Pye weeds'''. They are native to the United States and Canada, and have non-dissected foliage and pigmented flowers. The genus includes all the purple-flowering North American species of the genus ''[[Eupatorium]]'' as traditionally defined,<ref>{{aut|Siripun, Kunsiri Chaw & Schilling, Edward E.}} (2006): [https://web.archive.org/web/20071028053234/http://www.amjbot.org/cgi/content/full/93/2/319 Molecular confirmation of the hybrid origin of ''Eupatorium godfreyanum'' (Asteraceae)]. ''[[American Journal of Botany|Am. J. Bot.]]'' '''93'''(2): 319-325. [http://www.amjbot.org/cgi/reprint/93/2/319.pdf PDf fulltext]{{dead link|date=January 2024|bot=medic}}{{cbignore|bot=medic}}</ref> and most are grown as [[ornamental plant]]s, particularly in Europe and North America.

==Taxonomy==
''[[Eupatorium]]'' has recently undergone some revision and has been broken up into smaller genera.<ref>{{aut|Ito, Motomi; Watanabe, Kuniaki; Kita, Yoko; Kawahara, Takayuki; Crawford, D.J. & Yahara, Tetsukazu}} (2000): Phylogeny and Phytogeography of ''Eupatorium'' (Eupatorieae, Asteraceae): Insights from Sequence Data of the nrDNA ITS Regions and cpDNA RFLP. ''Journal of Plant Research'' '''113'''(1): 79-89. {{doi|10.1007/PL00013913}} (HTML abstract)</ref><ref name=ss>{{aut|Schmidt, Gregory J. & Schilling, Edward E.}} (2000): Phylogeny and biogeography of ''Eupatorium'' (Asteraceae: Eupatorieae) based on nuclear ITS sequence data. ''[[American Journal of Botany|Am. J. Bot.]]'' '''87'''(5): 716-726. {{doi|10.2307/2656858}} {{PMID|10811796}} [http://www.amjbot.org/cgi/reprint/87/5/716.pdf PDF fulltext]{{dead link|date=January 2024|bot=medic}}{{cbignore|bot=medic}}</ref>  Joe Pye weeds were initially included in the genus ''Eupatorium'', but as early as the 19th century Franco-American botanist [[Constantine Samuel Rafinesque]] proposed separating them into their own genus ''Eutrochium''.<ref name=Minnesota>"Spotted Joe Pye weed (Eutrochium maculatum)" at Minnesota Seasons web page. Retrieved 25 February 2023.</ref>{{efn|Or as '' Eupatorium sect. Verticillatum'' by [[Augustin Pyramus de Candolle|de Candolle]] in 1836.<ref>Alan Whittemore. "The Sectional Nomenclature of Eupatorium (Asteraceae)." ''Taxon.'' '''36:3''' (August 1987): 619. {{JSTOR|1221856}} {{doi|10.2307/1221856}}</ref>}}  Unaware of this,<ref name=Minnesota/> research botanists Robert M. King and Harold Robinson proposed assigning them to a new genus ''Eupatoriadelphus'' in 1970.<ref>R. M. King and H. Robinson. "Eupatorium, a Composite Genus of Arcto-Tertiary Distribution." ''Taxon.'' '''19.5''': 770 (October 1970). {{JSTOR|3562296}} {{doi|10.2307/1219289}}</ref>  This was widely accepted, and Joe Pye weeds began to be referred to as such.<ref name=Minnesota/>

In 1987, Robinson and King reincluded the genus ''Eupatoriadelphus'' in ''Eupatorium'', while recognizing this former genus as being the same group of plants as Rafinesque's ''Eutrochium''.<ref>Robert Merrill King and Harold Robinson. ''The Genera of the Eupatorieae (Asteraceae).'' Missouri Botanical Garden, 1987. [https://archive.org/details/mobot31753002042866/page/n74/mode/2up p. 65.] {{ISSN|0161-1542}}</ref>  This decision was also widely accepted.<ref>Eric E. Lamont. ''Taxonomy of Eupatorium Section Verticillata (Asteraceae).'' New York Botanical Garden, 1995. {{ISBN|9780893273910}}</ref>

Based on chloroplast DNA analysis published by Edward E, Schilling et al. in 1999,<ref>Edward E. Schilling, Jose L. Panero and Patricia B. Cox. [https://www.researchgate.net/profile/Edward-Schilling/publication/226392031_Chloroplast_DNA_restriction_site_data_support_a_narrowed_interpretation_ofEupatorium_Asteraceae/links/5508c6c90cf27e990e0cd91f/Chloroplast-DNA-restriction-site-data-support-a-narrowed-interpretation-ofEupatorium-Asteraceae.pdf "Chloroplast DNA restriction site data support a narrowed interpretation of ''Eupatorium'' (Asteraceae)."] ''Plant Systematics and Evolution.'' '''219(3/4)''':221 (January 1999).</ref> the Joe Pye weeds were again separated into their own genus, ''Eutrochium'',<ref>Gregory J Schmidt and Edward E Schilling. [https://bsapubs.onlinelibrary.wiley.com/doi/pdfdirect/10.2307/2656858 "Phylogeny and biogeography of Eupatorium (Asteraceae: Eupatorieae) based on nuclear ITS sequence data."] ''American Journal of Botany.'' '''87(5)''': 716. (May 2000). {{doi|10.2307/2656858}}</ref> as ''Eutrochium'' is the [[senior synonym]] of ''Eupatoriadelphus''.<ref>{{aut|Lamont, Eric E.}} (2004): New combinations in ''Eutrochium'', an earlier name for ''Eupatoriadelphus''. ''Sida'' '''21''': 901-902.</ref><ref name="FNA">{{eFloras|1|112473|Eutrochium |first=Eric E. |last=Lamont |volume=21}}</ref>  This usage quickly became formalized.<ref name=Minnesota/>

''Eupatorium'' in the revised sense (about 42 species of white-flowered plants from the [[temperate]] [[Northern hemisphere]]) is apparently a close relative of ''Eutrochium''.  In addition to flower color, another difference between ''Eutrochium'' and ''Eupatorium'' is that the former has mostly [[wiktionary:whorl|whorled]] leaves and the latter mostly opposite ones.<ref name="FNA" /><ref>{{eFloras|1|112351|Eupatorium |first1=Kunsiri Chaw |last1=Siripun |first2=Edward E. |last2=Schilling |volume=21}}</ref> ''Eupatorium'' and ''Eutrochium'' are both placed in the [[subtribe]] Eupatoriinae, but South American plants which have sometimes been placed in that subtribe, such as ''[[Stomatanthes]]'', seem to belong elsewhere in the tribe [[Eupatorieae]].<ref name=ss/>

;Species<ref>[http://www.theplantlist.org/tpl1.1/search?q=Eutrochium The Plant List, search for ''Eutrochium'']</ref>
* ''[[Eutrochium dubium]]'' <small>(Willdenow ex Poiret) E. E. Lamont</small> &ndash; coastal plain Joe-Pye weed
* ''[[Eutrochium fistulosum]]'' <small>(Barratt) E. E. Lamont</small> &ndash; hollow Joe-Pye weed
* ''[[Eutrochium maculatum]]'' <small>(Linnaeus) E. E. Lamont</small> &ndash; spotted Joe-Pye weed<ref>[http://plants.bees.net/gallery/view_photo.php?set_albumName=asteraceae&id=Photo_Eupatorium_maculatum_342A_7_30_01_Home "Eupatorium maculatum"] at Plants4Bees. [https://web.archive.org/web/20160303171030/http://plants.bees.net/gallery/view_photo.php?set_albumName=asteraceae&id=Photo_Eupatorium_maculatum_342A_7_30_01_Home Archived] on 3 March 2016.</ref>
* ''[[Eutrochium purpureum]]'' <small>(Linnaeus) E. E. Lamont</small> &ndash; sweet Joe-Pye weed, green-stemmed Joe-Pye weed, queen of the meadow, gravel root, kidney root, purple boneset
* ''[[Eutrochium steelei]]'' <small>(E. E. Lamont) E. E. Lamont</small>

== Uses ==
All of the Joe Pye weed species except ''E. steelei'' are widely cultivated as ornamental landscape plants.<ref>Richard Hawke. [https://www.chicagobotanic.org/downloads/planteval_notes/no37_joepyeweed.pdf "A Comparative Study of Joe-Pye Weeds (''Eutrochium'' spp.) and Their Relatives."] ''Plant Evaluation Notes.'' Chicago Botanic Garden. '''37''' (2014).</ref> Cultivars have been developed for a more compact habit (e.g. ''E. dubium'' ‘Little Joe’, ''E. dubium'' ‘Baby Joe’, ''E. maculatum'' ‘Little Red’) and varied flower color.

Joe Pye weeds have traditionally been ascribed with medicinal powers. A peer-reviewed study suggests that Joe Pye was a Mohican [[sachem]] named Schauquethqueat who lived in the mission town of Stockbridge, Massachusetts from {{circa}} 1740 to c. 1785 and who took as his Christian name, Joseph Pye.<ref>{{aut|Pearce, Richard B & Pringle, James S.}} (2017). Joe Pye, Joe Pye’s Law, and Joe-Pye-Weed: The History and Eponymy of the Common Name Joe-Pye-Weed for ''Eutrochium'' Species (''Asteraceae''),The Great Lakes Botanist, 56(3-4):177-200.[https://quod.lib.umich.edu/cgi/p/pod/dod-idx/joe-pye-joe-pyes-law-and-joe-pye-weed-the-history.pdf?c=mbot;idno=0497763.0056.303;format=pdf) Fulltext]</ref>  Sources (although without citation) claim the plant was used to treat typhus outbreaks<ref>{{aut|Audubon Society}} (1988). ''The Audubon Society Field Guide to North American Wildflowers, Eastern Region''.  New York: Alfred A. Knopf, Inc.</ref> and for the treatment of kidney stones and other urinary tract ailments.<ref>{{aut|Hemmerly, T. E.}} (2000). ''Appalachian Wildflowers''. Athens, Georgia: University of Georgia Press.</ref>

[[File:Bombus 6867.JPG|left|thumb|[[Bumblebee]] pollinating Joe-Pye weed]]
[[File:Whorled leaves of Joe Pye Weed.jpg|right|thumb|Whorled leaves of a Joe Pye Weed.  Pisgah National Forest, North Carolina, September 2012]]
{{clear left}}

==Notes==
{{Notelist}}

== References ==
{{Reflist}}

{{Commons category-inline}}
{{Taxonbar|from=Q1943382}}

[[Category:Eutrochium| ]]
[[Category:Asteraceae genera]]
[[Category:Flora of Northern America]]
[[Category:Taxa named by Constantine Samuel Rafinesque]]