Editing Clover (section)

== 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>