{{Short description|Genus of flowering plants}} {{Automatic taxobox |image=Isopyrum_thalictroides.jpg |image_caption=''Isopyrum thalictroides'' |taxon=Isopyrum |authority=L. |type_species=''Isopyrum thalictroides'' |type_species_authority=L. }}
'''''Isopyrum''''' is a genus of four species of flowering plants of the family Ranunculaceae native to Eurasia.<ref name=POWO>{{cite POWO|id=331677-2|title=''Isopyrum'' L.|access-date=27 January 2025}}</ref> ''Isopyrum'' species have white flowers with five sepals and five petals.
The genus was first described in 1753 by the biologist Carl Linnaeus. In 1920, the genus ''Paraquilegia'' was segregated out from ''Isopyrum'' to contain plants that are more morphologically aligned with members of the genus ''Aquilegia'' (columbines). Several species from North America and eastern Asia formerly included in ''Isopyrum'' have also been transferred to the genera ''Dichocarpum'' and ''Enemion''.<ref name=POWO-D>{{cite POWO|id=33120-1|title=''Dichocarpum'' W.T.Wang & P.K.Hsiao |access-date=2026-02-05}}</ref><ref name=POWO-E>{{cite POWO|id=33124-1|title=''Enemion'' Raf.|access-date=2026-02-05}}</ref>
==Description== thumb|right|Fruit and seeds of ''Isopyrum thalictroides'' ''Isopyrum'' is a genus of perennial herbs in the family Ranunculaceae. The smooth and glabrous stems stand erect. Leaves are biternate. The leaves attached to the base of the stem are pale green on the bottom and green on the top. Leaves attached to the stem have short petioles with white sheathes.<ref name=FOC>{{cite book|chapter-url= http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=116612|chapter=''Isopyrum''|title=Flora of China|volume=6|pages=275–276|date=2001|via=efloras.org}} (Note that the ''Flora of China'' was compiled before the genus ''Enemion'' was widely regarded as distinct, so may include characteristics applicable to that genus in its description)</ref>
Flowers on ''Isopyrum'' plants have radial symmetry. Each flower possesses five sepals and five petals. Sepals are white and petaloid. The petals are substantially smaller than the sepals. Each flower also features yellow anthers and between 20 and 30 stamens. There are between one and five pistils (female sex organs) to a flower.<ref name=FOC/>
''Isopyrum'' fruit are stored in follicles that appear in groups of one to five. Each bears numerous seeds. These seeds are smooth and have an ovoid to ellipsoid shape. The seeds can be varying shades of black.<ref name=FOC/>
==Taxonomy== The genus ''Isopyrum'' was first described by the Swedish biologist Carl Linnaeus in 1753.<ref name=FOC/> In 1920, British botanists James Ramsay Drummond and John Hutchinson published a paper, "A Revision of ''Isopyrum'' (Ranunculaceae) and Its Nearer Allies", in the Royal Botanic Gardens, Kew's ''Bulletin of Miscellaneous Information'' to address problems that had developed within the genus. Prior to their paper, the genus had permitted substantial morphological variance to coexist with certain species demonstrating greater affinities towards the genus ''Aquilegia'' (columbines).<ref>{{cite journal|title=A Revision of ''Isopyrum'' (Ranunculaceae) and Its Nearer Allies|journal=Bulletin of Miscellaneous Information|first1=J. R.|last1=Drummond|author-link1=James Ramsay Drummond|first2=J.|last2=Hutchinson|author-link2=John Hutchinson (botanist)|date=1920|volume=1920|number=5|pages=145–169|jstor=4107428|doi=10.2307/4107428}}</ref> Part of the pair's proposed resolution was creating ''Paraquilegia'' and expanding the genus ''Semiaquilegia''.<ref name=Nold>{{cite book|title=Columbines: ''Aquilegia'', ''Paraquilegia'', and ''Semiaquilegia''|first=Robert|last=Nold|publisher=Timber Press|date=2003|location=Portland, OR|isbn=0881925888}}</ref>{{rp|46}}
==Distribution== The Royal Botanic Gardens, Kew's ''Plants of the World Online'' (POWO) database, which accepts four species, considers ''Isopyrum'' as a solely Eurasian genus. POWO treats ''Isopyrum'' as native to Spain, France, much of Eastern Europe, and across Asia from Kazakhstan and Pakistan east through northern China to Korea and the far east of Russia. POWO also notes the genus as introduced in Denmark and Germany.<ref name=POWO/>
==Species== Many of the species formerly placed in ''Isopyrum'' are now placed in other genera of the Ranunculaceae, especially ''Enemion'' and ''Dichocarpum''. Accepted species include:<ref name="Cat. (2017) Isopyrum ">{{cite web|url=http://www.catalogueoflife.org/annual-checklist/2017/browse/tree/id/b6b4701de221b1c6825f3eef9e505a1c|title=Catalogue of Life - 2017 Annual Checklist : Taxonomic tree|website=www.catalogueoflife.org|access-date=2017-05-30|archive-date=2018-12-15|archive-url=https://web.archive.org/web/20181215222705/http://www.catalogueoflife.org/annual-checklist/2017/browse/tree/id/b6b4701de221b1c6825f3eef9e505a1c|url-status=dead}}</ref> * ''Isopyrum anemonoides'' <small>Kar. & Kir</small> * ''Isopyrum ludlowii'' <small>Tamura & Lauener</small> * ''Isopyrum manshuricum'' <small>(Komarov) Komarov ex W.T.Wang& Hsiao</small> * ''Isopyrum thalictroides'' <small>L.</small>
Synonyms include:<ref name="Cat (2017) ">{{cite web|url=http://www.catalogueoflife.org/annual-checklist/2017/search/all/key/Isopyrum/fossil/0/match/1/page/1/sort/direction/asc/direction/asc/direction/asc/direction/asc/direction/asc//direction/asc|title=Catalogue of Life - 2017 Annual Checklist : Search all names|website=www.catalogueoflife.org|access-date=2017-05-30|archive-date=2019-07-08|archive-url=https://web.archive.org/web/20190708164550/http://www.catalogueoflife.org/annual-checklist/2017/search/all/key/Isopyrum/fossil/0/match/1/page/1/sort/direction/asc/direction/asc/direction/asc/direction/asc/direction/asc//direction/asc|url-status=dead}}</ref><ref name=POWO/><ref name=POWO-D/><ref name=POWO-E/> * ''Isopyrum arisanense'' <small>(Hayata) Ohwi</small> = ''Dichocarpum arisanense'' <small>(Hayata) W.T.Wang & P.K.Hsiao</small> * ''Isopyrum auriculatum'' <small>Franch.</small> = ''Dichocarpum auriculatum'' <small>(Franch.) W.T.Wang & P.K.Hsiao</small> * ''Isopyrum biternatum'' <small>(Raf.) Torr. & A.Gray</small> = ''Enemion biternatum'' <small>Raf.</small> * ''Isopyrum dicarpon'' <small>Miq.</small> = ''Dichocarpum dicarpon'' <small>(Miq.) W.T.Wang & Hsiao</small> * ''Isopyrum hakonense'' <small>Maekawa & Tuyama ex Ohwi</small> = ''Dichocarpum hakonense'' <small>(Maekawa & Tuyama ex Ohwi) W.T.Wang & Hsiao</small> * ''Isopyrum hallii'' <small>A.Gray</small> = ''Enemion hallii'' <small>(A.Gray) J.R.Drumm. & Hutchinson</small> * ''Isopyrum leveilleanum'' <small>Nakai</small> = ''Semiaquilegia adoxoides'' <small>(DC.) Makino</small> * ''Isopyrum nipponicum'' <small>Franch.</small> = ''Dichocarpum nipponicum'' <small>(Franch.) W.T.Wang & Hsiao</small> * ''Isopyrum numajirianum'' <small>Makino</small> = ''Dichocarpum numajirianum'' <small>(Makino) W.T.Wang & Hsiao</small> * ''Isopyrum occidentale'' <small>Hook. & Arn.</small> = ''Enemion occidentale'' <small>(Hook. & Arn.) J.R.Drumm. & Hutch.</small> * ''Isopyrum pterigionocaudatum'' <small>Koidz.</small> = ''Dichocarpum nipponicum'' <small>(Franch.) W.T.Wang & Hsiao</small> * ''Isopyrum raddeanum'' <small>(Regel) Maxim.</small> = ''Enemion raddeanum'' <small>Regel</small> * ''Isopyrum savilei'' <small>Calder & Roy L.Taylor</small> = ''Enemion savilei'' <small>(Calder & Roy L.Taylor) Keener</small> * ''Isopyrum stipitatum'' <small>A.Gray</small> = ''Enemion stipitatum'' <small>(A.Gray) J.R.Drumm. & Hutch.</small> * ''Isopyrum stoloniferum'' <small>Maxim.</small> = ''Dichocarpum stoloniferum'' <small>(Maxim.) W.T.Wang & Hsiao</small> * ''Isopyrum trachyspermum'' <small>Maxim.</small> = ''Dichocarpum trachyspermum'' <small>(Maxim.) W.T.Wang & Hsiao</small> * ''Isopyrum uniflorum'' <small>Aitch. & Hemsl.</small> = ''Paraquilegia uniflora'' <small>(Aitch. & Hemsl.) J.Drumm. & Hutch.</small>
==References== * {{cite book | author=Pink, A. | url=https://www.gutenberg.org/ebooks/11892|title=Gardening for the Million| year=2004 | publisher=Project Gutenberg Literary Archive Foundation}} * [https://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?6434,6517 Jepson Manual Treatment] * [http://www.tropicos.org/Name/40032212?projectid=8 Tropicos.org - Species of Isopyrum] <references />
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Category:Isopyrum Category:Ranunculaceae genera Category:Botanical taxa named by Carl Linnaeus Category:Taxa described in 1753