Editing Hypericum perforatum (section)

== Taxonomy ==
[[File:Pflanzen der Heimat (Tafel 20) (6099921090).jpg|thumb|1913 [[botanical illustration]] of ''H. perforatum'' by [[Jost Fitschen]] in {{lang|de|Pflanzen der Heimat}}]]
''Hypericum perforatum'' was selected to be the [[type species]] around which the genus ''Hypericum'' is based because of its wide [[cosmopolitan distribution]]; it is the most common species of the genus in many of the areas it is found, and is one of the most widely known plants among the St John's worts in folklore and medicine.<ref name="Ernst-2003" />{{rp|19}} The current accepted placement of ''H. perforatum'' within its genus can be summarized as follows:<ref name=Robson-2002 />{{rp|62}}

''[[Hypericum]]''
: [[Hypericum subg. Hypericum|''Hypericum'' subg. ''Hypericum'']]
:: [[Hypericum sect. Hypericum|''Hypericum'' sect. ''Hypericum'']]
::: ''Hypericum'' subsect. ''Hypericum''
:::: ''Hypericum'' ser. ''Senanensia''
:::: ''Hypericum'' ser. ''Hypericum''
::::: ''[[Hypericum attenuatum|H. attenuatum]]''
::::: ''[[Hypericum iwate-littorale|H. iwate-littorale]]''
::::: ''[[Hypericum maculatum|H. maculatum]]''
::::: ''[[Hypericum momoseanum|H. momoseanum]]''
::::: ''H. perforatum''
::::: ''[[Hypericum scouleri|H. scouleri]]''
::::: ''[[Hypericum tetrapterum|H. tetrapterum]]''
::::: ''[[Hypericum tosaense|H. tosaense]]''
::::: ''[[Hypericum triquetrifolium|H. triquetrifolium]]''
::::: ''[[Hypericum undulatum|H. undulatum]]''

=== Phylogeny ===
''Hypericum perforatum'' has a [[Ploidy|chromosome count]] of 2n = 32. The likely reason for this is that the species is a [[Hybrid (biology)|hybrid]] between the very closely related ''H. maculatum subsp. immaculatum'' and ''[[Hypericum attenuatum|H. attenuatum]],'' which means it inherited sets of chromosomes from both parents and is [[allopolyploid]]. The two species almost certainly hybridized within [[Siberia|Siberia, Russia]]. The equation for this hybridization is:<ref name="Ernst-2003" />
{{Blockquote|text=''H. maculatum'' subsp. ''immaculatum'' (16) × ''H. attenuatum'' (16)×2 = ''H. perforatum'' (32)}}[[File:Hypericum × desetangsii 112458176.jpg|thumb|[[Hypericum × desetangsii|''Hypericum'' × ''desetangsii'']] is a hybrid between ''H. perforatum'' and ''H. maculatum''. It displays intermediate traits of the two species.]]Because of its hybrid origins, ''Hypericum perforatum'' is one of the few species within its genus that is able to further hybridize with other species, specifically those within [[Hypericum ser. Hypericum|''H.'' ser. ''Hypericum'']]. The hybrids that are descended from ''H. perforatum'' can be triploid (3 sets of chromosomes) to hexaploid (6 sets), depending on the chromosome count of the second parent species and the ploidy of the specific ''H. perforatum'' [[gamete]] that is fertilized or is fertilizing. The triploid offspring exhibit and a mix of traits from the two parents and pass them on to their offspring; the tetraploids also have a mix of traits, but often do not pass on the traits of both parents; the pentaploids are rarely distinguishable from ''H. perforatum''. Because of this, after many generations of hybridization a wide range of traits on a spectrum between the two hybridizing species can be observed in the wild.<ref name="Robson-2002">
{{Cite journal |last=Robson |first=Norman |author-link=Norman Robson (botanist) |date=2002 |title=Studies in the genus ''Hypericum'' {{small|L.}} (Guttiferae) 4(2). Section 9. ''Hypericum'' sensu lato (part 2): subsection 1. ''Hypericum'' series 1. ''Hypericum''. |url=https://www.biodiversitylibrary.org/page/2277196#page/2/mode/1up |journal=Bulletin of the British Museum (Natural History) Botany |volume=32 |pages=61–123 |via=[[Biodiversity Heritage Library]]}}</ref>{{rp|64}}

{| class="wikitable"
|+Hybrids involving ''H. perforatum<ref name="Robson-2002" />''
!Crossed with
!Hybrid name
!Chromosome number<ref group="a">Uncertainty in chromosome number notated by "?"</ref>
|-
|''[[Hypericum elegans|H. elegans]]''
|''H. perforatum × elegans''
|2n = 32?
|-
|''[[Hypericum tetrapterum|H. tetrapterum]]''
|''[[Hypericum × medium|''H.'' × ''medium'']]''
|2n = 24?
|-
|''[[Hypericum maculatum|H. maculatum]]'' [[Subspecies|ssp.]] ''maculatum''
|[[Hypericum × desetangsii|''H.'' × ''desetangsii'']] [[Hybrid name#Forms of hybrid names|nssp.]] ''carinthiacum''
|2n = 24/40
|-
|''H. maculatum'' ssp. ''immaculatum''
|''H.'' × ''desetangsii'' nssp. ''balcanicum''
|2n = 24/40?
|-
|''H. maculatum'' ssp. ''obtusiusculum''
|''H.'' × ''desetangsii'' nssp. ''desetangsii'' 
|2n = 40
|-
| colspan="3" |{{Reflist|group=a}}
|}

=== Etymology and common names===
The [[genus]] name ''Hypericum'' is possibly derived from the [[Greek language|Greek]] words {{Lang|el|hyper}} (above) and {{Lang|el|eikon}} (picture), in reference to the tradition of hanging the plant over religious [[icon]]s in the home.<ref>{{cite book |last1=Coombes |first1=Allen J. |title=The A to Z of plant names : a quick reference guide to 4000 garden plants |date=2012 |publisher=Timber Press, Inc. |isbn=978-1-60469-196-2 |location=Portland, Oregon |page=172}}</ref> The [[specific epithet]] ''perforatum'' is [[Latin]] and refers to the perforated appearance of the plant's leaves.<ref name="Manual" />

The common name ''St John's wort'' comes from the fact that its flowers and buds were commonly harvested at the time of the [[Midsummer|Midsummer festival]], which was later [[Christianization of saints and feasts|Christianized]] as [[Nativity of John the Baptist|St John's Feast Day]] on 24 June. It was believed that harvesting the flower at this time made its healing and magical powers more potent. The herb would be hung on house and stall doors on St John's Feast Day to ward off evil spirits and to safeguard against harm and sickness to people and livestock. In other traditions it was burned in bonfires for the protection of crops along with other herbs believed to be magical.<ref>{{cite book |last1=Trickey-Bapty |first1=Carolyn |url=https://archive.org/details/martyrsmiracles0000tric/page/133 |title=Martyrs and miracles |date=2001 |publisher=Testament Books |isbn=9780517164037 |location=New York |page=132 |access-date=26 July 2023}}</ref><ref name="Englishmans" /> Because of its supposed potency in warding off spirits, the plant was also known as ''fuga daemonum'' (loosely "demon-flight").<ref name="Ernst">Ernst 2003, p. 2.</ref> Many other similarly fanciful names have been used for it including ''devil's scourge'', ''Lord God's wonder plant'', and ''witch's herb''.<ref>World Health Organization, p. 149.</ref> In medieval [[Kent]] it was called ''herbe Ion'' (Ion in this case referring to "John") as recorded in the poem ''The Feate of Gardening''.<ref>{{cite book |last1=Cecil |first1=Evelyn |url=https://archive.org/details/historyofgardeni00cecil/page/71 |title=A history of Gardening in England |date=1896 |publisher=Bernard Quaritch |location=London |pages=71–72 |access-date=26 July 2023}}</ref> Other local names for ''Hypericum perforatum'' include ''balm of the warrior's wound'' in [[Somerset]], ''penny John'' in [[Norfolk]], ''rosin rose'' in [[Yorkshire]], and ''touch-and-heal'' in [[Northern Ireland]].<ref name="Englishmans">{{cite book |last1=Grigson |first1=Geoffrey |title=The Englishman's Flora |date=1960 |publisher=Phoenix House Ltd |location=London |pages=75–79 |edition=2nd |url=https://archive.org/details/englishmansflora0000geof/page/n75 |access-date=10 August 2023}}</ref> Locally in the United States, it may also be referred to as ''Tipton-weed'', ''goatweed'', or ''Klamath weed''.<ref name="NorthWestCoast">{{cite book |author=Charles Vancouver Piper |url=https://archive.org/details/cu31924001318322 |title=Flora of the Northwest Coast |author2=Rolla Kent Beattie |publisher=Press of the New era printing Company |year=1915 |page=[https://archive.org/details/cu31924001318322/page/n259 240]}}</ref><ref name="MBGarden">{{cite web |title=Hypericum perforatum |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=e198 |access-date=1 August 2023 |website=Plant Finder |publisher=Missouri Botanical Garden |location=St. Louis, Missouri}}</ref>

In the 21st century, any species of the genus ''Hypericum'' can be referred to as St John's wort. Therefore, it is more accurate to call ''Hypericum perforatum'' the ''common St John's wort'' or ''perforate St John's wort''.<ref name="Ernst" /><ref name="WHO" />

=== History ===
''Hypericum perforatum'' has been known and used since at least the first century. [[Pedanius Dioscorides]], an early [[Pharmacology|pharmacologist]], referred to either it or ''[[Hypericum empetrifolium|H. empetrifolium]]'' as ''akuron''.<ref name="Ernst" /> The species was first [[Species description|formally described]] by [[Carl Linnaeus]] in the second tome of ''[[Species Plantarum]]'' in 1753. In it, he gave the following brief description that would serve as the foundation for all subsequent identification of the species:<ref name="Species plantarum">{{Cite book |last1=Linné |first1=Carl |url=http://dx.doi.org/10.5962/bhl.title.669 |title=Species plantarum |last2=Salvius |first2=Lars |date=1753 |publisher=Impensis Laurentii Salvii |location=Holmiae |pages=785|doi=10.5962/bhl.title.669 }}</ref>

{{Text and translation|{{Lang|la|HYPERICUM floribus trigynis, caule ancipiti, foliis obtusis pellucido-punctatis.}}|''Hypericum'' with flowers that have three [[pistil]]s, [[Glossary of botanical terms#ancipital|ancipital]] stems, and obtuse leaves with pointed dots.}}

Linnaeus also noted the species' habitat in the "meadows of Europe" and gave a short account of previous mentions of the plant.<ref name="Species plantarum" /> While Linnaeus' taxonomic [[Principle of priority|priority]] for this species is not in question, there are a number of [[Synonym (taxonomy)#Botany|botanical synonyms]] that were published in the early years of formal [[botanical nomenclature]]. Gaterau published {{Lang|fr|Description des plantes qui croissent aux environs de Montauban}} in 1789 which described and called the species ''Hypericum officinale'', a name now considered to be [[Nomen illegitimum|illegitimate]] under the principle of priority. Likewise, the name ''Hypericum officinarum'' by the botanist [[Heinrich Johann Nepomuk von Crantz]] in 1763 also postdated Linnaeus' 1753 naming and description and is considered invalid.<ref name="POWO" />

=== Subdivision ===
[[File:Hypericum perforatum subsp. veronense Gavoi 950m 20072014.jpg|thumb|''H. perforatum'' ssp. ''veronense'']]
''Hypericum perforatum'' exhibits a great deal of variability in its appearance across its distribution. Thus, determining the exact nature of its [[Infraspecific name|infraspecific taxa]] is difficult because of the many intermediate forms that exist.<ref name="Robson-2002" />{{rp|88}}
* ''H. perforatum'' [[subspecies]] ''perforatum'' <small>Stjep.-Vesel.</small> is the type form of the species. It is distributed from the origin of the species in Siberia, west to central Europe, and east to northern Mongolia. The base changes as the plant grows from round to a broad wedge shape, and the seed capsule [[Vitta (botany)|vittae]] are present throughout the plant's life cycle and are almost always narrow.
** ''H. perforatum'' [[Variety (botany)|variety]] ''angustifolium'' <small>DC.</small> is a variety of the species that is found in drier climates within the range of ssp. ''perforatum''. It has leaves that look more like those of ssp. ''veronense'', but they have [[Petiole (botany)|leaf stalks]]; the glands on the seed capsule are also distinct.<ref name="Robson-2002" />{{rp|88}}
** ''H. perforatum'' var. ''humile'' <small>Stranski</small> can be found in parts of the southern Balkans. These plants possess smaller, more ring-shaped leaves and the seed capsules have flattish [[Vesicle (biology and chemistry)|vesicles]] on their surface. These appear to be adaptations of ssp. ''perforatum'' in response to the mountainous habitats of the region.<ref name="Robson-2002" />{{rp|89}}
* ''H. perforatum'' ssp. ''songaricum'' is likely the most primitive after ssp. ''perforatum''. Previously described as a variety by [[Karl Koch (botanist)|Karl Koch]], [[Norman Robson (botanist)|Norman Robson]] elevated the taxon to subspecies in his monograph of the genus. The leaves are sessile and have a heart-shaped base that partially surrounds the stem.<ref name="Robson-2002" />{{rp|89}}
** ''H. perforatum'' var. ''gracile'' has smaller leaves and is found in western Kazakhstan, southern Russia, and southern Ukraine. In the drier areas of this range the variety exhibits a dull grey-green color on the underside of its leaves.<ref name="Robson-2002" />{{rp|89}}
* ''H. perforatum'' ssp. ''veronense'' can be found in the Caucasus, across the Middle East to Tajikistan, and along North Africa to [[Macaronesia]]. These plants have narrower leaves and display diagonal vittae on the seed capsules. Where it meets the distribution of ssp. ''perforatum'' the two subspecies hybridize regularly.<ref name="Robson-2002" />{{rp|89}}
** ''H. perforatum'' var. ''ellipticum'' retains the diagonal vittae of the subspecies but the leaves are not as narrow. The variety is distributed in areas with greater moisture such as in the mountainous areas of Turkmenistan.<ref name="Robson-2002" />{{rp|89}}
* ''H. perforatum'' ssp. ''chinense'' is found across most of China and was introduced into Japan (under the synonym ''H. foliosissimum'' <small>Koidz.</small>). Both its leaves and flowers are smaller, and the flower clusters are smaller and more crowded on the ends of longer branches.<ref name="Robson-2002" />{{rp|89}}