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{{Short description|Genus of legumes}}{{redirect|Trifolium|the trematode parasite|Opisthorchiidae{{!}}Cladocystis trifolium|other uses|Clover (disambiguation)}}
{{Automatic taxobox
| name = Clover
| image = 79 Trifolium repens L.jpg
| image_caption = ''Trifolium repens'' (white clover)
| display_parents = 2
| taxon = Trifolium
| authority = [[Carl Linnaeus|L.]]
| subdivision_ranks = Subgenera and sections
| subdivision_ref = <ref name="species">{{cite web|url=http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?12357|access-date=2010-08-04|title=Species Nomenclature in GRIN|url-status=dead|archive-url=https://web.archive.org/web/20081014190106/http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?12357|archive-date=2008-10-14}}</ref>
| subdivision = subg. ''[[Chronosemium]]''<br>
subg. ''[[Trifolium subg. Trifolium|Trifolium]]''<br>
:sect. ''[[Glycyrrhizum]]''
:sect. ''[[Involucrarium]]''
:sect. ''[[Lupinaster]]''
:sect. ''[[Paramesus]]''
:sect. ''[[Trichocephalum]]''
:sect. ''[[Trifoliastrum]]''
:sect. ''[[Trifolium sect. Trifolium|Trifolium]]''
:sect. ''[[Vesicastrum]]''
| synonyms = 
*''Amarenus'' {{small|C.Presl (1831)}}
*''Amoria'' <small>C.Presl (1831)</small>
*''Bobrovia'' <small>A.P.Khokhr. (1998), nom. illeg.</small>
*''Calycomorphum'' {{small|C.Presl (1831)}}
*''Chrysaspis'' <small>Desv. (1827)</small>
*''Dactiphyllon'' {{small|Raf. (1818)}}
*''Dactiphyllum'' {{small|Raf. (1819)}}
*''Falcatula'' {{small|Brot. (1816 publ. 1817)}}
*''Galearia'' {{small|C.Presl (1831), nom. rej.}}
*''Lagopus'' {{small|Hill (1756)}}
*''Lagopus'' {{small|Bernh. (1800), nom. illeg.}}
*''Lojaconoa'' {{small|Bobrov (1967)}}
*''Loxospermum'' {{small|Hochst. (1846)}}
*''Lupinaster'' <small>Fabr. (1759)</small>
*''Micrantheum'' {{small|C.Presl (1831), nom. illeg.}}
*''Microphyton'' {{small|Fourr. (1868)}}
*''Mistyllus'' {{small|C.Presl (1831)}}
*''Ochreata'' {{small|(Lojac.) Bobrov (1967)}}
*''Paramesus'' {{small|C.Presl (1831)}}
*''Pentaphyllon'' {{small|Pers. (1807)}}
*''Triphylloides'' {{small|Moench (1794)}}
*''Ursia'' <small>Vassilcz. (1979)</small>
*''Ursifolium'' {{small|Doweld (2003)}}
*''Xerosphaera'' <small>Soják (1985 publ. 1986)</small>
| synonyms_ref = <ref name = powo>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:325471-2 ''Trifolium'' Tourn. ex L.] ''[[Plants of the World Online]]''. Retrieved 22 September 2023.</ref>
}}

'''Clovers''', also called '''trefoils''', are plants of the [[genus]] '''''Trifolium''''' ({{etymology|la|{{wikt-lang|la|tres}}|three||{{wikt-lang|la|folium}}|leaf}}), consisting of about 300 [[species]] of [[flowering plant]]s in the [[legume]] family [[Fabaceae]] originating in Europe. The genus has a [[cosmopolitan distribution]] with the highest diversity in the temperate [[Northern Hemisphere]], but many species also occur in [[South America]] and [[Africa]], including at high altitudes on mountains in the tropics. 

They are small [[annual plant|annual]], [[biennial plant|biennial]], or short-lived [[perennial plant|perennial]] [[herbaceous]] plants, typically growing up to {{cvt|30|cm|in}} tall. The [[leaves]] are [[trifoliate]] (rarely, they have more or fewer than three leaflets; the more (or fewer) leaflets the leaf has, the rarer it is; see [[four-leaf clover]]), with [[stipule]]s [[adnation|adnate]] to the leaf-stalk, and heads or dense spikes of small red, purple, white, or yellow flowers; the small, few-seeded pods are enclosed in the [[flower|calyx]].<ref name=EB1911/> Other closely related genera often called clovers include ''[[Melilotus]]'' (sweet clover) and ''[[Medicago]]'' ([[alfalfa]] or [[Calvary clover]]).

As [[legume]]s, clovers [[Nitrogen fixation|fix nitrogen]] using symbiotic bacteria in their [[root nodules]], and are used as an alternative or supplement to synthetic nitrogen [[fertilizer]]s. They are also valuable food source for grazing livestock and bees. The domestication of clover caused substantial increases in agricultural productivity.

== Cultivation history ==
[[File:A drop of dew on a clover.jpg|thumb|A clover with a dewdrop in the middle|alt=A clover with a drop of dew in the middle]]
[[File:Clovers & Zrebar.jpg|thumb|Clover flowers beside [[Zarivar Lake]] in [[Iran]]]]
[[File:Trifolium dubium RF.jpg|thumb|Lesser hop trefoil]]
[[File:Trifolium alpestre RF.jpg|thumb|Owl-head clover]]
[[File:2017-07-12 1655 clover.png|thumb|White clover]]
Clover was first domesticated in Spain in around the year 1000. During European urbanization, [[crop rotation]]s involving clover became essential for replacing the [[fixed nitrogen]] exported to cities as food.<ref name="world"/> Increased soil nitrogen levels from the spreading use of clover were one of the main reasons why European agricultural production in 1880 was about 275% of the production in 1750.<ref name="agri"/> Fields of clover, used as [[forage]] and newly-invented [[silage]], became an important part of the rural landscape;<ref name="world"/> adding clover made livestock feed more nutritious. Honey production also rose drastically, and clover remained the main nectar source for bees until the mid-twentieth century. Clover was carried around the world as a crop by [[European colonization|European colonists]], and some clover species became [[invasive species|invasive]] in some areas.<ref name="agri"/>

Imports of [[guano]]<ref name="agri"/> and the development of the [[Haber-Bosch process]] in the 20th century substantially displaced clover as a crop, with negative effects on pollinators,<ref name="world">{{cite journal |last1=Kjærgaard |first1=Thorkild |title=A Plant that Changed the World: The rise and fall of clover 1000-2000 |journal=Landscape Research |date=January 2003 |volume=28 |issue=1 |pages=41–49 |doi=10.1080/01426390306531 |bibcode=2003LandR..28...41K }}</ref> but in the 1990s and 2010s, the cost of industrially-fixed nitrogen rose substantially, approximately doubling, and reviving interest in forage mixes that include clover. As the fixation process is energy-intensive, prices are closely tied to energy prices. The 21st century has also seen interest in clover as a countermeasure to fight the global [[pollinator decline]].<ref name="agri">{{cite journal |last1=Harris |first1=Ciaran |last2=Ratnieks |first2=Francis L. W. |title=Clover in agriculture: combined benefits for bees, environment, and farmer |journal=Journal of Insect Conservation |date=June 2022 |volume=26 |issue=3 |pages=339–357 |doi=10.1007/s10841-021-00358-z |doi-access=free |bibcode=2022JICon..26..339H }}</ref>

==Cultivation==
Several species of clover are extensively cultivated as [[Fodder|fodder plants]]. The most widely cultivated clovers are [[Trifolium repens|white clover]], ''Trifolium repens'', and [[Trifolium pratense|red clover]], ''Trifolium pratense''. Clover, either sown alone or in mixture with [[ryegrass]], has for a long time formed a staple crop for silaging, for several reasons: it grows freely, shooting up again after repeated mowings; it produces an abundant crop; it is palatable to and nutritious for [[livestock]]; it [[Nitrogen fixation|fixes nitrogen]] using symbiotic bacteria in its [[root nodules]], reducing the need for synthetic [[fertilizer]]s; it grows in a great range of [[soil]]s and [[climate]]s; and it is appropriate for either pasturage or [[green manure|green compost]]ing.<ref name=EB1911/>

{{anchor|clover sickness}}
In many areas, particularly on [[acidic soil]], clover is short-lived because of a combination of insect pests, diseases and nutrient balance; this is known as "clover sickness". When [[crop rotation]]s are managed so that clover does not recur at intervals shorter than eight years, it grows with much of its pristine vigor.<ref name=EB1911/>

Clovers are most efficiently pollinated by [[bumblebee]]s, which have declined as a result of agricultural intensification.<ref name="Bumbles make beeline for gardens, study suggests">[https://www.bbc.co.uk/news/science-environment-11822844 Bumbles make beeline for gardens, study suggests] {{Webarchive|url=https://web.archive.org/web/20180518105032/http://www.bbc.co.uk/news/science-environment-11822844 |date=2018-05-18 }} Retrieved 27 November 2010.</ref> [[Honeybee]]s can also pollinate clover, and [[beekeeper]]s are often in heavy demand from farmers with clover pastures. Farmers reap the benefits of increased reseeding that occurs with increased bee activity, which means that future clover yields remain abundant. Beekeepers benefit from the clover bloom, as clover is one of the main [[Northern Nectar Sources for Honeybees|nectar sources for honeybees]].<ref>{{cite book |last1=Oertel |first1=Everett |title=Beekeeping in the United States |date=1967 |publisher=U.S. Department of Agriculture |page=16 |url=https://books.google.com/books?id=iiuhYroAuuoC&pg=PA16 |language=en |access-date=2022-03-11 |archive-date=2023-01-16 |archive-url=https://web.archive.org/web/20230116073109/https://books.google.com/books?id=iiuhYroAuuoC&pg=PA16 |url-status=live }}</ref>

''[[Trifolium repens]]'', white or Dutch clover, is a perennial abundant in meadows and good pastures. The flowers are white or pinkish, becoming brown and deflexed as the corolla fades. ''[[Trifolium hybridum]]'', alsike or Swedish clover, is a perennial which was introduced early in the 19th century and has now become naturalized in Britain. The flowers are white or rosy, and resemble those of ''Trifolium repens''. ''[[Trifolium medium]]'', meadow or zigzag clover, a perennial with straggling [[flexuous]] stems and rose-purple flowers,<ref name=EB1911/> has potential for interbreeding with ''T. pratense'' to produce perennial crop plants.<ref>{{cite journal |author1=Isobe, S. |author2=Sawai, A. |author3=Yamaguchi, H. |author4=Gau, M. |author5=Uchiyama, K. |year=2002 |title=Breeding potential of the backcross progenies of a hybrid between ''Trifolium medium'' × ''T. pratense'' to ''T. pratense'' |journal=Canadian Journal of Plant Science |volume=82 |issue=2 |pages=395–399 |doi=10.4141/P01-034 |doi-access=free }}</ref>

Other species are: ''[[Trifolium arvense]]'', hare's-foot trefoil; found in fields and dry pastures, a soft hairy plant with minute white or pale pink flowers and feathery sepals; ''[[Trifolium fragiferum]]'', strawberry clover, with globose, rose-purple heads and swollen calyxes; ''[[Trifolium campestre]]'', hop trefoil, on dry pastures and roadsides, the heads of pale yellow flowers suggesting miniature hops; and the somewhat similar ''[[Trifolium dubium]]'', common in pastures and roadsides, with smaller heads and small yellow flowers turning dark brown.<ref name=EB1911/>

== Uses ==
Bears, game animals, ruminants and birds forage for and eat clover, and it is edible by humans,<ref>{{cite book | url=https://archive.org/details/fieldguidetoedib00angi/page/60/mode/2up | isbn=978-0-8117-0616-2 | title=Field guide to edible wild plants | date=1974 | publisher=[Harrisburg, Pa.] Stackpole Books }}</ref> although [[trifolium pratense|red clover]] in particular contains [[phytoestrogen]]s that may carry risks during pregnancy. The plant is a traditional Native American food,<ref>{{Cite web |last=DAWSON |first=ARTHUR |date=2023-04-26 |title=Indigenous tribes utilized clover and the plant inspired a local city's name |url=https://www.pressdemocrat.com/article/news/indigenous-tribes-utilized-clover-and-the-plant-inspired-a-citys-name/ |access-date=2024-04-30 |website=Santa Rosa Press Democrat |language=en-US}}</ref> which is eaten both raw and after drying and smoking the roots. The seeds from the blossoms are used to make bread.<ref name="Angier-1974">{{Cite book|last=Angier|first=Bradford|url=https://archive.org/details/fieldguidetoedib00angi/page/60/mode/2up|title=Field Guide to Edible Wild Plants|publisher=Stackpole Books|year=1974|isbn=0-8117-0616-8|location=Harrisburg, PA|pages=60|oclc=799792|author-link=Bradford Angier}}</ref> It is also possible to make tea from the blossoms.<ref name="Angier-1974" />

== Symbolism ==
[[Shamrock]], the traditional Irish symbol, which was coined by [[Saint Patrick]] for the [[Holy Trinity]], is commonly associated with clover, although alternatively sometimes with the various species within the genus ''[[Oxalis]]'', which are also trifoliate.<ref>{{Cite web|url=http://www.finegardening.com/shamrock-oxalis|title=Shamrock (Oxalis)|website=Fine Gardening|access-date=February 28, 2017|archive-date=March 1, 2017|archive-url=https://web.archive.org/web/20170301180720/http://www.finegardening.com/shamrock-oxalis|url-status=live}}</ref>

Clovers occasionally have four leaflets, instead of the usual three. These [[four-leaf clover]]s, like other rarities, are considered lucky.<ref name=EB1911>{{EB1911|wstitle=Clover|volume=6|page=561|inline=1}}</ref> Clovers can also have five, six, or more leaflets, but these are rarer still. The clover's outer leaf structure varies in physical orientation.

The record for most leaflets is 63, set on August 2, 2023, by Yoshiharu Watanabe in Japan.<ref>{{cite web|title=Most leaves on a clover|url=https://www.guinnessworldrecords.com/world-records/most-leaves-on-a-clover/|archive-url=https://web.archive.org/web/20240808181811/https://www.guinnessworldrecords.com/world-records/most-leaves-on-a-clover/|archive-date=August 8, 2024|access-date=August 8, 2024|publisher=[[Guinness World Records]]|url-status=live}}</ref> The previous record holder, Shigeo Obara, had discovered an 18-leaf clover in 2002,<ref>{{cite web | url=http://www.guinnessworldrecords.com/records/natural_world/plant_world/clover_-_most_leaves.aspx | title=Clover - Most Leaves | publisher=[[Guinness World Records]] | access-date=22 December 2016 | archive-url=https://web.archive.org/web/20080325145509/http://www.guinnessworldrecords.com/records/natural_world/plant_world/clover_-_most_leaves.aspx | archive-date=March 25, 2008 | url-status=dead}}</ref> a 21-leaf clover in 2008<ref>{{cite web|title=21-leaf Clover Sets Record|url=https://www.neatorama.com/2008/06/11/21-leaf-clover-sets-record|archive-url=https://web.archive.org/web/20090722022314/http://www.neatorama.com/2008/06/11/21-leaf-clover-sets-record|date=June 11, 2008|archive-date=July 22, 2009|url-status=live|website=Neatorama|access-date=August 8, 2024}}</ref> and a 56-leaf clover in 2009,<ref>{{cite web|title=Most Leaves on a Clover|url=http://www.guinnessworldrecords.com/world-records/most-leaves-on-a-clover/|publisher=Guinness World Records|access-date=2011-04-23|archive-date=2015-03-19|archive-url=https://web.archive.org/web/20150319035902/http://www.guinnessworldrecords.com/world-records/most-leaves-on-a-clover|url-status=deviated}}</ref> also in Japan.

*A common [[idiom]] is "to be (or to live) in clover", meaning to live a carefree life of ease, comfort, or prosperity.<ref>{{Cite web|date=June 26, 2021|title=Cambridge Dictionary|url=https://dictionary.cambridge.org/dictionary/english/live-be-in-clover|url-status=live|access-date=June 26, 2021|website=Cambridge Dictionary|archive-url=https://web.archive.org/web/20151004114544/http://dictionary.cambridge.org/dictionary/english/live-be-in-clover |archive-date=2015-10-04 }}</ref>

* A common saying in surgery [regarding the appearance of wound after hemorrhoidectomy] is "If it looks like clover, the trouble is over; if it looks like dahlia, it’s surely a failure."

*A [[cloverleaf interchange]] is named for the resemblance to the leaflets of a (four-leaf) clover when viewed from the air.<ref>{{cite book|first=Michael|last=Pollard|title=Travel by Road and Rail|publisher=Schoolhouse Press|place=Independence, Ohio|year=1986|isbn=9780808610403|page=31}}</ref>

<gallery widths="200px" heights="200px">
File:4-leaf clover.JPG|Four-leaf white clover (''[[Trifolium repens]]'')
File:Five-leaf Clover, Megan McCarty128.jpg|Five-leaf red clover (''[[Trifolium pratense]]'')
</gallery>

== Phylogeny ==
The first extensive classification of ''Trifolium'' had been done by [[Michael Zohary]] and David Heller, and it was subsequently released in 1984. They divided the genus into eight sections: ''Lotoidea, Paramesus, Mistyllus, Vesicamridula, Chronosemium, Trifolium, Trichoecephalum,'' and ''Involucrarium,'' with ''Lotoidea'' placed most [[Basal (phylogenetics)|basally]].<ref>{{Cite book|title=The genus Trifolium|last=Zohary|first=Michael|date=1984|publisher=Israel Academy of Sciences and Humanities|others=Heller, D.|isbn=978-9652080561|location=Jerusalem|oclc=11057949}}</ref> Within this classification system, ''[[Trifolium repens]]'' falls within section ''Lotoidea'', the largest and least heterogeneous section. ''Lotoidea'' contains species from America, Africa, and Eurasia, considered a clade because of their inflorescence shape, floral structure, and legume that protrudes from the calyx. However, these traits are not unique to the section, and are shared with many other species in other sections. Zohary and Heller argued that the presence of these traits in other sections proved the basal position of ''Lotoidea'', because they were ancestral. Aside from considering this section basal, they did not propose relationships between other sections.
Since then, molecular data has both questioned and confirmed the proposed phylogeny from Zohary and Heller. A genus-wide molecular study has since proposed a new classification system, made up of two subgenera, ''Chronosemium'' and ''Trifolium.''<ref>{{Cite journal|last1=Ellison|first1=Nick W.|last2=Liston|first2=Aaron|last3=Steiner|first3=Jeffrey J.|last4=Williams|first4=Warren M.|last5=Taylor|first5=Norman L.|title=Molecular phylogenetics of the clover genus (Trifolium—Leguminosae)|journal=Molecular Phylogenetics and Evolution|volume=39|issue=3|pages=688–705|doi=10.1016/j.ympev.2006.01.004|pmid=16483799|year=2006|bibcode=2006MolPE..39..688E }}</ref> This recent reclassification further divides subgenus ''Trifolium'' into eight sections. The molecular data supports the monophyletic nature of three sections proposed by Zohary and Heller (''Tripholium, Paramesus,'' and ''Trichoecepalum''), but not of ''Lotoidea'' (members of this section have since been reclassified into five other sections). Other molecular studies, although smaller, support the need to reorganize ''Lotoidea.''<ref>{{Cite journal|last1=Vižintin|first1=Liliana|last2=Javornik|first2=Branka|last3=Bohanec|first3=Borut|title=Genetic characterization of selected Trifolium species as revealed by nuclear DNA content and ITS rDNA region analysis|journal=Plant Science|volume=170|issue=4|pages=859–866|doi=10.1016/j.plantsci.2005.12.007|year=2006|bibcode=2006PlnSc.170..859V }}</ref><ref>{{Cite journal|last1=Watson|first1=L. E.|last2=Sayed-Ahmed|first2=H.|last3=Badr|first3=A.|date=2000-09-01|title=Molecular phylogeny of Old WorldTrifolium (Fabaceae), based on plastid and nuclear markers|journal=Plant Systematics and Evolution|language=en|volume=224|issue=3–4|pages=153–171|doi=10.1007/BF00986340|bibcode=2000PSyEv.224..153W |s2cid=45350663|issn=0378-2697}}</ref>

== Species ==
<!--could we subdivide this list by native continent?-->
291 species of ''Trifolium'' are accepted:<ref name = powo/>
{{div col|colwidth=21em}}
* ''[[Trifolium absconditum]]'' {{small|Molinari}}
* ''[[Trifolium acaule]]'' <small>Steud. ex A.Rich.</small>
* ''[[Trifolium affine]]'' <small>C.Presl</small>
* ''[[Trifolium acutiflorum]]'' {{small|Murb.}}
* ''[[Trifolium × adulterinum]]'' {{small|Beyer}}
* ''[[Trifolium africanum]]'' <small>Ser.</small>
* ''[[Trifolium aintabense]]'' <small>Boiss. & Hausskn.</small>
* ''[[Trifolium albopurpureum]]'' <small>Torr. & A. Gray</small> – rancheria clover
* ''[[Trifolium alexandrinum]]'' <small>[[Carl Linnaeus|L.]]</small> – Egyptian clover, berseem clover
* ''[[Trifolium alpestre]]'' <small>[[Carl Linnaeus|L.]]</small> – owl-head clover
* ''[[Trifolium alpinum]]'' <small>[[Carl Linnaeus|L.]]</small> – alpine clover
* ''[[Trifolium alsadami]]'' {{small|Post}}
* ''[[Trifolium amabile]]'' <small>Kunth</small>
* ''[[Trifolium ambiguum]]'' <small>M. Bieb.</small>
* ''[[Trifolium amoenum]]'' <small>[[Edward Lee Greene|Greene]]</small> – showy Indian clover
* ''[[Trifolium amphianthum]]'' {{small|Torr. & A.Gray}}
* ''[[Trifolium andersonii]]'' <small>A. Gray</small> – Anderson's clover or fiveleaf clover
* ''[[Trifolium andinum]]'' <small>Nutt.</small> – Intermountain clover
* ''[[Trifolium andricum]]'' <small>Lassen</small>
* ''[[Trifolium angulatum]]'' <small>Waldst. & Kit.</small>
* ''[[Trifolium angustifolium]]'' <small>[[Carl Linnaeus|L.]]</small>
* ''[[Trifolium ankaratrense]]'' {{small|Bosser}}
* ''[[Trifolium apertum]]'' <small>Bobrov</small>
* ''[[Trifolium appendiculatum]]'' {{small|Lojac.}}
* ''[[Trifolium argutum]]'' <small>Banks & Sol.</small>
* ''[[Trifolium arvense]]'' <small>[[Carl Linnaeus|L.]]</small> – hare's-foot clover
* ''[[Trifolium attenuatum]]'' <small>[[Edward Lee Greene|Greene]]</small>
* ''[[Trifolium aureum]]'' <small>Pollich</small> – large hop trefoil
* ''[[Trifolium baccarinii]]'' <small>Chiov.</small>
* ''[[Trifolium badium]]'' <small>Schreb.</small>
* ''[[Trifolium barbigerum]]'' <small>Torr.</small> – bearded clover
* ''[[Trifolium barbulatum]]'' {{small|(Freyn & Sint.) Zohary}}
* ''[[Trifolium barnebyi]]'' <small>(Isely) Dorn & Lichvar</small>
* ''[[Trifolium batmanicum]]'' <small>Katzn.</small>
* ''[[Trifolium beckwithii]]'' <small>W.H.Brewer ''ex'' S.Watson</small> – Beckwith's clover
* ''[[Trifolium bejariense]]'' <small>Moric.</small>
* ''[[Trifolium × bertrandii]]'' {{small|Rouy}}
* ''[[Trifolium berytheum]]'' <small>Boiss. & C.I.Blanche</small>
* ''[[Trifolium biebersteinii]]'' {{small|Khalilov}}
* ''[[Trifolium bifidum]]'' <small>A.Gray</small> – notchleaf clover
* ''[[Trifolium bilineatum]]'' <small>Fresen.</small>
* ''[[Trifolium billardierei]]'' <small>Spreng.</small>
* ''[[Trifolium bithynicum]]'' {{small|Boiss.}}
* ''[[Trifolium bivonae]]'' <small>Guss.</small>
* ''[[Trifolium blancheanum]]'' <small>Boiss.</small>
* ''[[Trifolium bobrovii]]'' {{small|Khalilov}}
* ''[[Trifolium bocconei]]'' <small>Savi</small>
* ''[[Trifolium boissieri]]'' <small>Guss.</small>
* ''[[Trifolium bolanderi]]'' <small>A.Gray</small>
* ''[[Trifolium bordsilovskyi]]'' {{small|Grossh.}}
* ''[[Trifolium brandegeei]]'' <small>S.Watson</small>
* ''[[Trifolium breweri]]'' <small>S. Watson</small> – forest clover
* ''[[Trifolium brutium]]'' <small>Ten.</small>
* ''[[Trifolium buckwestiorum]]'' <small>Isely</small> – Santa Cruz clover
* ''[[Trifolium bullatum]]'' <small>Boiss. & Hausskn.</small>
* ''[[Trifolium burchellianum]]'' <small>Ser.</small>
* ''[[Trifolium calcaricum]]'' <small>J.L.Collins & Wieboldt</small>
* ''[[Trifolium calocephalum]]'' <small>Fresen.</small>
* ''[[Trifolium campestre]]'' <small>[[Johann Christian Daniel von Schreber|Schreb.]]</small> – hop trefoil
* ''[[Trifolium canescens]]'' <small>Willd.</small>
* ''[[Trifolium carolinianum]]'' <small>Michx.</small>
* ''[[Trifolium caudatum]]'' <small>Boiss.</small>
* ''[[Trifolium cernuum]]'' <small>Brot.</small>
* ''[[Trifolium cheranganiense]]'' <small>J.B.Gillett</small>
* ''[[Trifolium cherleri]]'' <small>L.</small>
* ''[[Trifolium chilaloense]]'' <small>Thulin</small>
* ''[[Trifolium chilense]]'' <small>Hook. & Arn.</small>
* ''[[Trifolium chlorotrichum]]'' <small>Boiss. & Balansa</small>
* ''[[Trifolium ciliolatum]]'' <small>Benth.</small> – foothill clover
* ''[[Trifolium circumdatum]]'' <small>Kunze</small>
* ''[[Trifolium clusii]]'' <small>Godr.</small>
* ''[[Trifolium clypeatum]]'' <small>L.</small>
* ''[[Trifolium congestum]]'' <small>Guss.</small>
* ''[[Trifolium constantinopolitanum]]'' <small>Ser.</small>
* ''[[Trifolium cryptopodium]]'' <small>Steud. ''ex'' A. Rich.</small>
* ''[[Trifolium cyathiferum]]'' <small>Lindl.</small> – cup clover
* ''[[Trifolium dalmaticum]]'' <small>Vis.</small>
* ''[[Trifolium dasyphyllum]]'' <small>Torr. & A.Gray</small>
* ''[[Trifolium dasyurum]]'' <small>C.Presl</small>
* ''[[Trifolium davisii]]'' <small>E.Hossain</small>
* ''[[Trifolium decorum]]'' <small>Chiov.</small>
* ''[[Trifolium dedeckerae]]'' {{small|J.M.Gillett}}
* ''[[Trifolium depauperatum]]'' <small>Desv.</small> – cowbag clover, balloon sack clover, or poverty clover
* ''[[Trifolium dichotomum]]'' <small>Hook. & Arn.</small>
* ''[[Trifolium dichroanthoides]]'' <small>Rech.f.</small>
* ''[[Trifolium dichroanthum]]'' <small>Boiss.</small>
* ''[[Trifolium diffusum]]'' <small>Ehrh.</small>
* ''[[Trifolium dolopium]]'' <small>Heldr. & Hochst. ''ex'' Gibelli & Belli</small>
* ''[[Trifolium douglasii]]'' <small>House</small>
* ''[[Trifolium dubium]]'' <small>[[John Sibthorp|Sibth.]]</small> – lesser hop trefoil
* ''[[Trifolium echinatum]]'' <small>M.Bieb.</small>
* ''[[Trifolium egrissicum]]'' {{small|Mikheev & Magulaev}}
* ''[[Trifolium elgonense]]'' <small>J.B.Gillett</small>
* ''[[Trifolium elizabethiae]]'' {{small|Grossh.}}
* ''[[Trifolium eriocephalum]]'' <small>Nutt.</small> – woollyhead clover
* ''[[Trifolium eriosphaerum]]'' <small>Boiss.</small>
* ''[[Trifolium erubescens]]'' <small>Fenzl</small>
* ''[[Trifolium euxinum]]'' <small>Zohary</small>
* ''[[Trifolium eximium]]'' <small>Stephan ''ex'' Ser.</small>
* ''[[Trifolium farayense]]'' {{small|Mouterde}}
* ''[[Trifolium fergan-karaeri]]'' {{small|M.Keskin}}
* ''[[Trifolium fontanum]]'' {{small|Bobrov}}
* ''[[Trifolium fragiferum]]'' <small>L.</small> – strawberry clover
* ''[[Trifolium friscanum]]'' <small>(S.L.Welsh) S.L.Welsh</small>
* ''[[Trifolium fucatum]]'' <small>Lindl.</small> – bull clover or sour clover
* ''[[Trifolium gemellum]]'' <small>Pourr. ''ex'' Willd.</small>
* ''[[Trifolium gillettianum]]'' <small>Jacq.-Fél.</small>
* ''[[Trifolium glanduliferum]]'' <small>Boiss.</small>
* ''[[Trifolium globosum]]'' <small>L.</small>
* ''[[Trifolium glomeratum]]'' <small>L.</small> – clustered clover or bush clover
* ''[[Trifolium gordeievii]]'' <small>(Kom.) Z.Wei</small>
* ''[[Trifolium gracilentum]]'' <small>Torr. & A.Gray</small> – pinpoint clover
* ''[[Trifolium grandiflorum]]'' <small>Schreb.</small>
* ''[[Trifolium gymnocarpon]]'' <small>Nutt.</small> – hollyleaf clover
* ''[[Trifolium hatschbachii]]'' {{small|Vincent & Butterworth}}
* ''[[Trifolium haussknechtii]]'' <small>Boiss.</small>
* ''[[Trifolium haydenii]]'' <small>Porter</small>
* ''[[Trifolium heldreichianum]]'' <small>(Gibelli & Belli) Hausskn.</small>
* ''[[Trifolium hickeyi]]'' {{small|T.K.Ahlq. & Vincent}}
* ''[[Trifolium hirtum]]'' <small>All.</small> – rose clover
* ''[[Trifolium howellii]]'' <small>S.Watson</small> – canyon clover or Howell's clover
* ''[[Trifolium humile]]'' {{small|Ball}}
* ''[[Trifolium hybridum]]'' <small>L.</small> – Alsike clover
* ''[[Trifolium hydrophilum]]'' {{small|Greene}}
* ''[[Trifolium incarnatum]]'' <small>L.</small> – crimson clover
* ''[[Trifolium infamia-ponertii]]'' {{small|Greuter}}
* ''[[Trifolium israeliticum]]'' <small>Zohary & Katzn.</small>
* ''[[Trifolium isthmocarpum]]'' <small>Brot.</small>
* ''[[Trifolium jokerstii]]'' <small>Vincent & Rand.Morgan</small>
* ''[[Trifolium juliani]]'' <small>Batt.</small>
* ''[[Trifolium kentuckiense]]'' <small>Chapel & Vincent</small>
* ''[[Trifolium kingii]]'' <small>S.Watson</small>
* ''[[Trifolium lanceolatum]]'' <small>(J.B.Gillett) J.B.Gillett</small>
* ''[[Trifolium lappaceum]]'' <small>L.</small>
* ''[[Trifolium latifolium]]'' <small>(Hook.) Greene</small>
* ''[[Trifolium latinum]]'' <small>Sebast.</small>
* ''[[Trifolium leibergii]]'' <small>A.Nelson & J.F.Macbr.</small> – Leiberg's clover
* ''[[Trifolium lemmonii]]'' <small>S.Watson</small> – Lemmon's clover
* ''[[Trifolium leucanthum]]'' <small>M.Bieb.</small>
* ''[[Trifolium ligusticum]]'' <small>Balb. ''ex'' Loisel.</small>
* ''[[Trifolium longidentatum]]'' <small>Nábelek</small>
* ''[[Trifolium longipes]]'' <small>Nutt.</small> – longstalk clover
* ''[[Trifolium lucanicum]]'' <small>Gasp.</small>
* ''[[Trifolium lugardii]]'' <small>Bullock</small>
* ''[[Trifolium lupinaster]]'' <small>L.</small>
* ''[[Trifolium macilentum]]'' <small>Greene</small>
* ''[[Trifolium macraei]]'' <small>Hook. & Arn.</small> – Chilean clover, double-head clover, or MacRae's clover
* ''[[Trifolium macrocephalum]]'' <small>(Pursh) Poir.</small> – largehead clover
* ''[[Trifolium masaiense]]'' <small>J.B.Gillett</small>
* ''[[Trifolium mattirolianum]]'' <small>Chiov.</small>
* ''[[Trifolium mazanderanicum]]'' <small>Rech.f.</small>
* ''[[Trifolium medium]]'' <small>L.</small> – zigzag clover
* ''[[Trifolium meduseum]]'' <small>C.I.Blanche ''ex'' Boiss.</small>
* ''[[Trifolium meironense]]'' <small>Zohary & Lerner</small>
* ''[[Trifolium mesogitanum]]'' {{small|Boiss.}}
* ''[[Trifolium michaelis]]'' {{small|Greuter}}
* ''[[Trifolium michelianum]]'' <small>Savi</small>
* ''[[Trifolium micranthum]]'' <small>Viv.</small>
* ''[[Trifolium microcephalum]]'' <small>Pursh</small> – smallhead clover
* ''[[Trifolium microdon]]'' <small>Hook. & Arn.</small> – thimble clover
* ''[[Trifolium miegeanum]]'' <small>Maire</small>
* ''[[Trifolium minutissimum]]'' {{small|D.Heller & Zohary}}
* ''[[Trifolium modestum]]'' {{small|Boiss.}}
* ''[[Trifolium monanthum]]'' <small>A.Gray</small> – mountain carpet clover
* ''[[Trifolium montanum]]'' <small>L.</small>
* ''[[Trifolium multinerve]]'' <small>A. Rich.</small>
* ''[[Trifolium multistriatum]]'' <small>W.D.J.Koch</small>
* ''[[Trifolium mutabile]]'' <small>Port.</small>
* ''[[Trifolium nanum]]'' <small>Torr.</small>
* ''[[Trifolium nerimaniae]]'' <small>M.Keskin</small>
* ''[[Trifolium × neyrautii]]'' {{small|Rouy}}
* ''[[Trifolium nigrescens]]'' <small>[[Domenico Viviani|Viv.]]</small>
* ''[[Trifolium noricum]]'' <small>Wulfen</small>
* ''[[Trifolium obscurum]]'' <small>Savi</small>
* ''[[Trifolium obtusiflorum]]'' <small>Hook.</small> – clammy clover
* ''[[Trifolium occidentale]]'' <small>Coombe</small>
* ''[[Trifolium ochroleucon]]'' <small>Huds.</small> - sulphur clover
* ''[[Trifolium oliganthum]]'' <small>Steud.</small> – fewflower clover
* ''[[Trifolium olivaceum]]'' {{small|Greene}}
* ''[[Trifolium orbelicum]]'' {{small|Velen.}}
* ''[[Trifolium ornithopodioides]]'' <small>L.</small>
* ''[[Trifolium owyheense]]'' <small>Gilkey</small>
* ''[[Trifolium pachycalyx]]'' <small>Zohary</small>
* ''[[Trifolium palaestinum]]'' <small>Boiss.</small>
* ''[[Trifolium pallescens]]'' <small>Schreb.</small>
* ''[[Trifolium pallidum]]'' <small>Waldst. & Kit.</small>
* ''[[Trifolium palmeri]]'' {{small|S.Watson}}
* ''[[Trifolium pamphylicum]]'' {{small|Boiss. & Heldr.}}
* ''[[Trifolium pannonicum]]'' <small>Jacq.</small> – Hungarian clover
* ''[[Trifolium parnassi]]'' <small>Boiss. & Spruner</small>
* ''[[Trifolium parryi]]'' <small>A.Gray</small>
* ''[[Trifolium patens]]'' <small>Schreb.</small><!-- BiolConserv137:248. -->
* ''[[Trifolium patulum]]'' <small>Tausch</small>
* ''[[Trifolium pauciflorum]]'' <small>d'Urv.</small>
* ''[[Trifolium × permixtum]]'' {{small|Neuman}}
* ''[[Trifolium peruvianum]]'' <small>Vogel</small>
* ''[[Trifolium philistaeum]]'' <small>Zohary</small>
* ''[[Trifolium phitosianum]]'' <small>N.Böhling, Greuter & Raus</small>
* ''[[Trifolium phleoides]]'' <small>Pourr. ''ex'' Willd.</small>
* ''[[Trifolium physanthum]]'' <small>Hook. & Arn.</small>
* ''[[Trifolium physodes]]'' <small>Steven ''ex'' M. Bieb.</small>
* ''[[Trifolium pichisermollii]]'' <small>J.B.Gillett</small>
* ''[[Trifolium pignantii]]'' <small>Fauché. & Chaub.</small>
* ''[[Trifolium pilczii]]'' <small>Adamović</small>
* ''[[Trifolium pilulare]]'' <small>Boiss.</small>
* ''[[Trifolium piorkowskii]]'' <small>Rand.Morgan & A.L.Barber</small>
* ''[[Trifolium plebeium]]'' <small>Boiss.</small>
* ''[[Trifolium plumosum]]'' <small>Douglas ex Hook.</small>
* ''[[Trifolium polymorphum]]'' <small>Poir.</small>
* ''[[Trifolium polyodon]]'' <small>Greene</small>
* ''[[Trifolium polyphyllum]]'' <small>C.A.Mey.</small>
* ''[[Trifolium polystachyum]]'' <small>Fresen.</small>
* ''[[Trifolium praetermissum]]'' <small>Greuter, Pleger & Raus.</small>
* ''[[Trifolium pratense]]'' <small>L.</small> – red clover<ref>{{cite web |url=http://naturalon.com/top-10-best-teas-for-detox-and-cleansing/view-all/ |title=Detox and Cleansing |access-date=March 12, 2016 |archive-url=https://web.archive.org/web/20160306052824/http://naturalon.com/top-10-best-teas-for-detox-and-cleansing/view-all |archive-date=March 6, 2016 |url-status=dead |date=2014-12-24 }}</ref>
* ''[[Trifolium productum]]'' {{small|Greene}}
* ''[[Trifolium prophetarum]]'' <small>M. Hossain</small>
* ''[[Trifolium pseudomedium]]'' {{small|Hausskn.}}
* ''[[Trifolium pseudostriatum]]'' <small>Baker f.</small>
* ''[[Trifolium pulchellum]]'' {{small|Schischk.}}
* ''[[Trifolium purpureum]]'' <small> Loisel.</small>
* ''[[Trifolium purseglovei]]'' <small>J. B. Gillett</small>
* ''[[Trifolium quartinianum]]'' <small>A. Rich.</small>
* ''[[Trifolium radicosum]]'' <small>Boiss. & Hohen.</small>
* ''[[Trifolium rechingeri]]'' {{small|Rothm.}}
* ''[[Trifolium reflexum]]'' <small>L.</small> – buffalo clover
* ''[[Trifolium repens]]'' <small>L.</small> – [[shamrock]] (white clover)
* ''[[Trifolium resupinatum]]'' <small>L.</small> – Persian clover, shaftal
* ''[[Trifolium retusum]]'' <small>L.</small>
* ''[[Trifolium × retyezaticum]]'' {{small|Nyár.}}
* ''[[Trifolium rhizomatosum]]'' {{small|O.Schwarz}}
* ''[[Trifolium rhombeum]]'' {{small|S.Schauer}}
* ''[[Trifolium riograndense]]'' <small>Burkart</small>
* ''[[Trifolium rollinsii]]'' {{small|J.M.Gillett}}
* ''[[Trifolium roussaeanum]]'' <small>Boiss.</small>
* ''[[Trifolium rubens]]'' <small>L.</small>
* ''[[Trifolium rueppellianum]]'' <small>Fresen.</small>
* ''[[Trifolium salmoneum]]'' <small>Mouterde</small>
* ''[[Trifolium sannineum]]'' {{small|Mouterde}}
* ''[[Trifolium sarosiense]]'' {{small|Hazsl.}}
* ''[[Trifolium saxatile]]'' <small>All.</small>
* ''[[Trifolium scabrum]]'' <small>L.</small>
* ''[[Trifolium schimperi]]'' <small>(Hochst.) A.Rich.</small>
* ''[[Trifolium schneideri]]'' {{small|Standl.}}
* ''[[Trifolium × schwarzii]]'' {{small|Wein}}
* ''[[Trifolium scutatum]]'' <small>Boiss.</small>
* ''[[Trifolium sebastiani]]'' <small>Savi</small>
* ''[[Trifolium semipilosum]]'' <small>Fresen.</small>
* ''[[Trifolium setiferum]]'' <small>Boiss.</small>
* ''[[Trifolium simense]]'' <small>Fresen.</small>
* ''[[Trifolium sintenisii]]'' <small>Freyn</small>
* ''[[Trifolium siskiyouense]]'' <small>J.M.Gillett</small>
* ''[[Trifolium somalense]]'' <small>Taub. ex Harms</small>
* ''[[Trifolium sonorense]]'' {{small|T.K.Ahlq. & Vincent}}
* ''[[Trifolium spadiceum]]'' <small>L.</small>
* ''[[Trifolium spananthum]]'' <small>Thulin</small>
* ''[[Trifolium spumosum]]'' <small>L.</small>
* ''[[Trifolium squamosum]]'' (or ''maritimum'') <small>L.</small> – sea clover
* ''[[Trifolium squarrosum]]'' <small>L.</small>
* ''[[Trifolium stellatum]]'' <small>L.</small>
* ''[[Trifolium steudneri]]'' <small>Schweinf.</small>
* ''[[Trifolium stipulaceum]]'' <small>Thunb.</small>
* ''[[Trifolium stoloniferum]]'' <small>Muhl. ''ex'' A. Eaton</small> – running buffalo clover
* ''[[Trifolium stolzii]]'' <small>Harms</small>
* ''[[Trifolium striatum]]'' <small>L.</small> – knotted clover
* ''[[Trifolium strictum]]'' <small>L.</small>
* ''[[Trifolium subterraneum]]'' <small>L.</small> – subterranean clover
* ''[[Trifolium suffocatum]]'' <small>L.</small>
* ''[[Trifolium sylvaticum]]'' <small>Gérard</small>
* ''[[Trifolium tembense]]'' <small>Fresen.</small>
* ''[[Trifolium tenuifolium]]'' {{small|Ten.}}
* ''[[Trifolium thalii]]'' <small>Vill.</small>
* ''[[Trifolium thompsonii]]'' <small>C.V.Morton</small> – Thompson's clover
* ''[[Trifolium tomentosum]]'' <small>L.</small>
* ''[[Trifolium × traplii]]'' {{small|Domin}}
* ''[[Trifolium triaristatum]]'' <small>Bertero ''ex'' Colla</small>
* ''[[Trifolium trichocalyx]]'' <small>A.Heller</small> – Monterey clover
* ''[[Trifolium trichocephalum]]'' <small>M. Bieb.</small>
* ''[[Trifolium trichopterum]]'' <small>Pančić</small>
* ''[[Trifolium tumens]]'' <small>Steven ''ex'' M.Bieb.</small>
* ''[[Trifolium ukingense]]'' <small>Harms</small>
* ''[[Trifolium uniflorum]]'' <small>L.</small>
* ''[[Trifolium usambarense]]'' <small>Taub.</small>
* ''[[Trifolium variegatum]]'' <small>Nutt.</small> – whitetip clover
* ''[[Trifolium vavilovii]]'' <small>Eig</small>
* ''[[Trifolium velebiticum]]'' <small>Degen</small>
* ''[[Trifolium velenovskyi]]'' <small>Vandas</small>
* ''[[Trifolium vernum]]'' <small>Phil.</small>
* ''[[Trifolium vesiculosum]]'' <small>Savi</small>
* ''[[Trifolium vestitum]]'' <small>D.Heller & Zohary</small>
* ''[[Trifolium virginicum]]'' <small>Small</small>
* ''[[Trifolium wentzelianum]]'' <small>Harms</small>
* ''[[Trifolium wettsteinii]]'' <small>Dörfl. & Hayek</small>
* ''[[Trifolium wigginsii]]'' <small>J. M. Gillett</small>
* ''[[Trifolium willdenovii]]'' <small>[[Curt Polycarp Joachim Sprengel|Spreng.]]</small> − tomcat clover
* ''[[Trifolium wormskioldii]]'' <small>[[Johann Georg Christian Lehmann|Lehm.]]</small> – cow clover
* ''[[Trifolium xanthinum]]'' {{small|Freyn}}
{{div col end}}

== See also ==
* [[Clover honey]]
* [[Clover lawn]]
* [[Cloverleaf quasar]]
* [[Green manure]]

== References ==
{{Reflist}}

== External links ==
* {{Commons category-inline|Trifolium}}
* [http://www.quattrofolium.com/ Quattrofolium]
* [http://www.northernbushcraft.com/plants/clover/notes.htm Edibility of clover]: Edible parts and visual identification of wild clover.
* [http://extension.msstate.edu/news/feature-story/2004/clover-provides-nitrogen-for-soil-forage-for-cattle Nitrogen fixation]

{{Taxonbar|from=Q101538}}
{{Authority control}}

[[Category:Forages]]
[[Category:Garden plants]]
[[Category:Groundcovers]]
[[Category:Nitrogen-fixing crops]]
[[Category:Trifolium| ]]
[[Category:Botanical taxa named by Carl Linnaeus]]