View source for Fabaceae

{{short description|Family of legume flowering plants}}
{{About|Fabaceae s.l. (or Leguminosae), as defined by the APG System|Fabaceae s.s. (or Papilionaceae), as defined by less modern systems|Faboideae}}
{{Distinguish|Fagaceae}}
{{Use dmy dates|date=May 2015}}
{{Automatic taxobox
| fossil_range = {{fossilrange|Paleocene|recent|ref=<ref name=mobot>{{Cite web |title=Fabales|url=https://mobot.org/MOBOT/research/APweb/orders/fabalesweb.htm|access-date=2023-06-16 |website=www.mobot.org}}</ref>}}
| image = Flowering kudzu.jpg
| image_caption = [[Kudzu]] (''Pueraria lobata'')
| taxon = Fabaceae
| authority = [[John Lindley|Lindl.]]<ref name=APGIII2009>{{cite journal |last=Angiosperm Phylogeny Group |year=2009 |title=An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III |journal=Botanical Journal of the Linnean Society |volume=161 |issue=2 |pages=105–121 |doi=10.1111/j.1095-8339.2009.00996.x |doi-access=free |hdl=10654/18083 |hdl-access=free }}</ref> (Leguminosae [[Antoine-Laurent de Jussieu|Jussieu]], [[nomen conservandum|nom. cons.]]).<ref name="Watson">{{cite web |url=http://delta-intkey.com/angio/www/legumino.htm |title=The families of flowering plants: Leguminosae |access-date=9 February 2008 |author1=Watson L. |author2=Dallwitz, M. J. |date=2007-06-01 |archive-date=8 October 2017 |archive-url=https://web.archive.org/web/20171008231217/http://delta-intkey.com/angio/www/legumino.htm |url-status=dead }}</ref>
| type_genus = ''Faba'' <small>(now included in ''[[Vicia]]'')</small>
| type_genus_authority = Mill.
| subdivision_ranks = Subfamilies
| subdivision_ref = <ref name="6subfamilies"/>
| subdivision = * [[Caesalpinioideae]] [[Alphonse Pyrame de Candolle|DC.]]
* [[Cercidoideae]] <small>LPWG</small>
* [[Detarioideae]] <small>Burmeist.</small>
* [[Dialioideae]] <small>LPWG</small>
* [[Duparquetioideae]] <small>LPWG</small>
* [[Faboideae]] <small>Rudd</small> ([[Synonym (taxonomy)|syn.]] Papilionoideae <small>DC.</small>)
| range_map = Legume Biogeography.svg
| range_map_alt = The biomes occupied by Fabaceae
| range_map_caption = Fabaceae distribution map. Legumes are found in four major [[biome]]s: '''<span style="color:#007000;">tropical forest</span>''', '''<span style="color:#00FF00;">temperate</span>''', '''<span style="color:#D1E231;">grass</span>''', and '''<span style="color:#987654;">succulent</span>'''.<ref name="Schrire2" />
| diversity_link = Fabaceae#Taxonomy
| diversity = 730 genera and 19,400 species
| synonyms = * Caesalpiniaceae <small>[[R.Br.]]</small>
* Cassiaceae <small>[[Heinrich Friedrich Link|Link]]</small>
* Ceratoniaceae <small>[[Heinrich Friedrich Link|Link]]</small>
* Detariaceae <small>([[DC.]]) [[Johann Jakob Hess (botanist)|Hess]]</small>
* Hedysareae (Hedysaraceae) <small>[[Jacob Georg Agardh|Agardh]]</small>
* Lathyraceae <small>Burnett</small>
* Lotaceae <small>Burnett</small>
* Mimosaceae <small>R.Br.</small>
* Papilionaceae <small>[[Giseke]]</small>
* Phaseolaceae <small>[[Patricio Ponce de León|Ponce de León]] & Alvares</small>
* Robiniaceae <small>[[Welw.]]</small>
* Swartziaceae <small>(DC.) [[Bartl.]]</small>
}}

The '''Fabaceae''' ({{IPAc-en|f|ə|'|b|eɪ|s|i|.|iː|,_|-|ˌ|aɪ}}) or '''Leguminosae''',<ref name="ICN">[http://www.iapt-taxon.org/nomen/main.php?page=art18 International Code of Nomenclature for algae, fungi, and plants.] {{Webarchive|url=https://web.archive.org/web/20130927152429/http://www.iapt-taxon.org/nomen/main.php?page=art18 |date=27 September 2013 }}  Article 18.5 states: "The following names, of long usage, are treated as validly published:  ....Leguminosae (nom. alt.: Fabaceae; type: Faba Mill. [= Vicia L.]); ...
When the Papilionaceae are regarded as a family distinct from the remainder of the Leguminosae, the name Papilionaceae is conserved against Leguminosae." English pronunciations are as follows: {{IPAc-en|f|ə|ˈ|b|eɪ|s|i|(|i|)|,_|-|s|i|aɪ|,_|-|s|i|eɪ}}, {{IPAc-en|l|ə|ˌ|g|j|uː|m|ə|ˈ|n|oʊ|s|i}} and {{IPAc-en|p|ə|ˌ|p|ɪ|l|i|oʊ-|ˈ|n|eɪ|s|i|i}}.</ref> commonly known as the '''legume''', '''pea''', or '''bean family''', are a large and agriculturally important [[family (biology)|family]] of [[flowering plant]]s.  It includes [[tree]]s, [[shrub]]s, and [[Perennial plant|perennial]] or [[annual plant|annual]] [[herbaceous plant]]s, which are easily recognized by their [[fruit]] ([[legume]]) and their compound, [[stipule|stipulate]] leaves. The family is widely distributed, and is the third-largest [[land plant]] family in number of species, behind only the [[Orchidaceae]] and [[Asteraceae]], with about 765 genera and nearly 20,000 known species.<ref>{{cite encyclopedia |title=List of plants in the family Fabaceae |url=https://www.britannica.com/topic/list-of-plants-in-the-family-Fabaceae-2021803 |encyclopedia=Encyclopædia Britannica |access-date=28 April 2021}}</ref><ref name="Christenhusz-Byng2016">{{cite journal |author1=Christenhusz, M. J. M. |author2=Byng, J. W. | year = 2016 | title = The number of known plants species in the world and its annual increase | journal = Phytotaxa | volume = 261 | pages = 201–217 | url = http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 | doi = 10.11646/phytotaxa.261.3.1 | issue = 3 | doi-access = free }}</ref><ref name="Judd2002">Judd, W. S., Campbell, C. S. Kellogg, E. A. Stevens, P.F. Donoghue, M. J. (2002), Plant systematics: a phylogenetic approach, Sinauer Axxoc, 287–292. {{ISBN|0-87893-403-0}}.</ref><ref name="Stevens 2001">{{cite journal|url = http://www.mobot.org/MOBOT/Research/APweb/orders/fabalesweb.htm#Fabaceae
|title = Fabaceae
|access-date=28 April 2008
|author = Stevens, P. F.
|journal = Angiosperm Phylogeny Website. Version 7 May 2006
}}</ref>

The five largest genera of the family are ''[[Astragalus (plant)|Astragalus]]'' (over 3,000 species), ''[[Acacia]]'' (over 1,000 species), ''[[Indigofera]]'' (around 700 species), ''[[Crotalaria]]'' (around 700 species), and ''[[Mimosa]]'' (around 400 species), which constitute about a quarter of all legume species. The c. 19,000 known [[Legume|legume species]] amount to about 7% of flowering plant species.<ref name="Judd2002" /><ref name="Magallónsperm">{{cite journal |author=Magallón, S. A., and Sanderson, M. J. |year=2001 |title=Absolute diversification rates in angiosperm clades |journal=Evolution |volume=55 |issue=9 |pages=1762–1780 |pmid=11681732 |last2=Sanderson |doi=10.1111/j.0014-3820.2001.tb00826.x |s2cid=38691512 |df=dmy-all |doi-access=free }}</ref>  Fabaceae is the most common family found in tropical rainforests and dry forests of the [[Americas]] and [[Africa]].<ref name="Burnham">{{cite journal|last1=Burnham|first1=R. J.|last2=Johnson|first2=K. R.|date=2004|title=South American palaeobotany and the origins of neotropical rainforests|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=359|issue=1450|pages=1595–1610|doi=10.1098/rstb.2004.1531|pmid=15519975|pmc=1693437}}</ref>

Recent molecular and morphological evidence supports the fact that the Fabaceae is a single [[monophyly|monophyletic]] family.<ref name="Lewis">Lewis G., Schrire B., Mackinder B. and Lock M. 2005. (eds.) Legumes of the world. The Royal Botanic Gardens, Kew, Reino Unido. 577 pages. 2005. {{ISBN|1-900347-80-6}}.</ref> This conclusion has been supported not only by the degree of interrelation shown by different groups within the family compared with that found among the Leguminosae and their closest relations, but also by all the recent [[phylogenetics|phylogenetic studies]] based on [[DNA]] sequences.<ref name="doyle">Doyle, J. J., J. A. Chappill, C.D. Bailey, & T. Kajita. 2000. Towards a comprehensive phylogeny of legumes: evidence from rbcL sequences and non-molecular data. pp. 1 -20 in Advances in legume systematics, part 9, (P. S. Herendeen and A. Bruneau, eds.). Royal Botanic Gardens, Kew, UK.</ref><ref name="Kajita">{{cite journal | last1 = Kajita | first1 = T. | last2 = Ohashi | first2 = H. | last3 = Tateishi | first3 = Y. | last4 = Bailey | first4 = C. D. | last5 = Doyle | first5 = J. J. | year = 2001 | title = ''rbcL'' and legume phylogeny, with particular reference to Phaseoleae, Millettieae, and allies | url = https://www.researchgate.net/publication/232696212 | journal = Systematic Botany | volume = 26 | issue = 3| pages = 515–536 | jstor = 3093979 | doi = 10.1043/0363-6445-26.3.515 | doi-broken-date = 1 November 2024 }}</ref><ref name="Wojciechowski">{{cite journal | author=Wojciechowski, M. F., M. Lavin and M. J. Sanderson |year=2004 |title=A phylogeny of legumes (Leguminosae) based on analysis of the plastid matK gene resolves many well-supported sub clades within the family | journal=American Journal of Botany | volume=91 |issue=11 |pages=1846–1862 |pmid=21652332 |last2=Lavin |last3=Sanderson |doi=10.3732/ajb.91.11.1846 |doi-access=free }}</ref> These studies confirm that the Fabaceae are a monophyletic group that is closely related to the families [[Polygalaceae]], [[Surianaceae]] and [[Quillajaceae]] and that they belong to the order [[Fabales]].<ref name="Angiosperm">{{cite journal |author=Angiosperm Phylogeny Group [APG] |year=2003 |title=An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II |journal=Botanical Journal of the Linnean Society |volume=141 |issue=4 |pages=399–436 |doi=10.1046/j.1095-8339.2003.t01-1-00158.x |doi-access=free }}</ref>

Along with the [[cereal]]s, some [[fruit]]s and tropical roots, a number of Leguminosae have been a staple human food for millennia and their use is closely related to [[human evolution]].<ref name="uno">Burkart, A. Leguminosas. ''In:'' Dimitri, M. 1987. ''Enciclopedia Argentina de Agricultura y Jardinería''. Tomo I. Descripción de plantas cultivadas. Editorial ACME S.A.C.I., Buenos Aires. pages: 467–538.</ref>

The family Fabaceae includes a number of plants that are common in agriculture including ''Glycine max'' ([[soybean]]), ''[[Phaseolus]]'' (beans), ''Pisum sativum'' ([[pea]]), ''Cicer arietinum'' ([[chickpea]]s), ''Vicia faba'' ([[Vicia faba|broad bean]]),  ''Medicago sativa'' ([[alfalfa]]), ''Arachis hypogaea'' ([[peanut]]), ''[[Ceratonia siliqua]]'' (carob), ''Trigonella foenum-graecum'' ([[fenugreek]]), and ''[[Glycyrrhiza glabra]]'' ([[liquorice]]). A number of species are also weedy [[Pest (organism)|pests]] in different parts of the world, including ''[[Cytisus scoparius]]'' (broom), ''[[Robinia pseudoacacia]]'' (black locust)'', [[Ulex europaeus]]'' (gorse), ''[[Pueraria montana]]'' (kudzu), and a number of ''[[Lupinus]]'' species.

== Etymology ==
The name  'Fabaceae' comes from the defunct genus ''Faba'', now included in ''[[Vicia]]''. The term "faba" comes from Latin, and appears to simply mean "bean". Leguminosae is an older name still considered valid,<ref name=ICN /> and refers to the [[fruit]] of these plants, which are called [[legume]]s.

== Description ==
[[File:Gymnocladus-dioicus.jpg|thumb|upright|The fruit of ''[[Gymnocladus dioicus]]'']]
Fabaceae range in habit from giant [[tree]]s (like ''[[Koompassia excelsa]]'') to small [[annual plant|annual]] [[Herbaceous plant|herbs]], with the majority being herbaceous perennials. Plants have indeterminate inflorescences, which are sometimes reduced to a single flower. The flowers have a short [[hypanthium]] and a single [[carpel]] with a short [[gynophore]], and after fertilization produce fruits that are legumes.

=== Growth habit ===
The Fabaceae have a wide variety of [[Habit (biology)|growth forms]], including trees, shrubs, herbaceous plants, and even [[vine]]s or [[liana]]s. The herbaceous plants can be annuals, [[biennial plant|biennials]], or perennials, without basal or terminal leaf aggregations. Many Legumes have tendrils. They are upright plants, [[epiphyte]]s, or vines. The latter support themselves by means of shoots that twist around a support or through cauline or foliar [[tendril]]s. Plants can be [[heliophyte]]s, [[mesophyte]]s, or [[xerophyte]]s.<ref name="Watson" /><ref name="Judd2002" />

=== Leaves ===
The leaves are usually [[phyllotaxis|alternate]] and compound. Most often they are even- or odd-[[pinnate]]ly compound (e.g. ''[[Caragana]]'' and ''[[Robinia]]'' respectively), often trifoliate (e.g. ''[[Trifolium]]'', ''[[Medicago]]'') and rarely [[Glossary of leaf shapes|palmate]]ly compound (e.g. ''[[Lupinus]]''), in the Mimosoideae and the Caesalpinioideae commonly bipinnate (e.g. ''[[Acacia]]'', ''[[Mimosa]]''). They always have [[stipule]]s, which can be leaf-like (e.g. ''[[Pisum]]''), thorn-like (e.g. ''[[Robinia]]'') or be rather inconspicuous. Leaf margins are entire or, occasionally, [[Leaf#Terminology|serrate]]. Both the leaves and the leaflets often have wrinkled [[pulvinus|pulvini]] to permit [[nastic movements]]. In some species, leaflets have evolved into [[tendril]]s (e.g. ''[[Vicia]]'').<ref name="Watson" /><ref name="Judd2002" /><ref name="uno" />

Many species have leaves with structures that attract [[ant]]s which protect the plant from herbivore insects (a form of [[Mutualism (biology)|mutualism]]). [[Nectar#Extrafloral nectaries|Extrafloral nectaries]] are common among the Mimosoideae and the Caesalpinioideae, and are also found in some Faboideae (e.g. ''[[Vicia sativa]]''). In some ''[[Acacia]]'', the modified hollow stipules are inhabited by ants and are known as [[domatia]].

=== Roots ===
{{Main|Root nodule}}
Many Fabaceae host [[bacteria]] in their roots within structures called [[root nodule]]s. These bacteria, known as [[rhizobia]], have the ability to take [[nitrogen]] gas (N<sub>2</sub>) out of the air and convert it to a form of nitrogen that is usable to the host plant ( [[Nitrate|NO<sub>3</sub><sup>−</sup>]] or [[Ammonia|NH<sub>3</sub>]] ). This process is called [[nitrogen fixation]]. The legume, acting as a host, and [[rhizobia]], acting as a provider of usable nitrate, form a [[symbiosis|symbiotic]] relationship. Members of the [[Phaseoleae]] genus ''[[Apios]]'' form tubers, which can be edible.<ref name=Seabrook>{{cite thesis|last=Seabrook|first=Janet E.A.|title=A Biosystematic Study of the Genus ''Apios'' Fabricius (Leguminosae) with Special Reference to ''Apios americana'' Medikus|degree=M.Sc. |publisher=University of New Brunswick, Fredericton, NB|year=1973}}</ref>

=== Flowers ===
{{redirect|Pea flower|the flour produced from peas|pea flour}}
{{See also|Papilionaceous flower}}
[[File:Wisteria sinensis anatomia en.svg|thumb|right|300px|A flower of ''[[Wisteria sinensis]]'', Faboideae. Two petals have been removed to show stamens and pistil]]
The [[flower]]s often have five generally fused [[sepal]]s and five free [[petal]]s. They are generally [[plant sexuality|hermaphroditic]] and have a short [[hypanthium]], usually cup-shaped. There are normally ten [[stamen]]s and one elongated superior [[ovary (plants)|ovary]], with a curved [[style (botany)|style]]. They are usually arranged in [[Inflorescence#Terminal flower|indeterminate]] [[inflorescence]]s. Fabaceae are typically [[entomophily|entomophilous]] plants (i.e. they are [[pollinated]] by [[insect]]s), and the flowers are usually showy to attract [[pollinator]]s.

In the [[Caesalpinioideae]], the flowers are often [[zygomorphic]], as in ''[[Cercis]]'', or nearly symmetrical with five equal petals, as in ''[[Bauhinia]]''. The upper petal is the innermost one, unlike in the [[Faboideae]]. Some species, like some in the genus ''[[Senna (plant)|Senna]]'', have asymmetric flowers, with one of the lower petals larger than the opposing one, and the style bent to one side. The calyx, corolla, or stamens can be showy in this group.

In the [[Mimosoideae]], the flowers are [[actinomorphic]] and arranged in globose inflorescences. The petals are small and the stamens, which can be more than just 10, have long, coloured filaments, which are the showiest part of the flower. All of the flowers in an inflorescence open at once.

In the [[Faboideae]], the flowers are zygomorphic, and have a [[Papilionaceous flower|specialized structure]]. The upper petal, called the banner or standard, is large and envelops the rest of the petals in bud, often reflexing when the flower blooms. The two adjacent petals, the wings, surround the two bottom petals. The two bottom petals are fused together at the apex (remaining free at the base), forming a boat-like structure called the keel. The stamens are always ten in number, and their filaments can be fused in various configurations, often in a group of nine stamens plus one separate stamen. Various genes in the ''CYCLOIDEA (CYC)/DICHOTOMA (DICH)'' family are expressed in the upper (also called dorsal or adaxial) petal; in some species, such as ''[[Cadia (plant)|Cadia]]'', these genes are expressed throughout the flower, producing a radially symmetrical flower.<ref>{{cite journal | title = An apparent reversal in floral symmetry in the legume Cadia is a homeotic transformation |author1=Hélène L. Citerne |author2=R. Toby Pennington |author3=Quentin C. B. Cronk | doi = 10.1073/pnas.0600986103 | journal = PNAS | date = 8 August 2006 | volume = 103 | issue = 32 | pages = 12017–12020 | pmc = 1567690 | pmid = 16880394 | bibcode = 2006PNAS..10312017C |doi-access=free }}</ref>

=== Fruit ===
{{Main|Legume}}
[[File:(MHNT) Vicia sativa - immature fruit.jpg|thumb|right|Legume of ''[[Vicia sativa]]'']]
The ovary most typically develops into a [[legume]]. A legume is a [[Fruit#Simple fruit|simple dry fruit]] that usually [[Dehiscence (botany)|dehisces]] (opens along a seam) on two sides. A common name for this type of fruit is a "pod", although that can also be applied to a few other fruit types. A few species have evolved [[Samara (fruit)|samarae]], [[loment]]s, [[follicle (fruit)|follicles]], indehiscent legumes, [[achene]]s, [[drupe]]s, and [[berries]] from the basic legume fruit.

=== Physiology and biochemistry ===
The Fabaceae are rarely [[cyanogenic]]. Where they are, the cyanogenic compounds are derived from [[tyrosine]], [[phenylalanine]] or [[leucine]]. They frequently contain [[alkaloids]]. [[Proanthocyanidin]]s can be present either as [[cyanidin]] or [[delphinidine]] or both at the same time.  [[Flavonoid]]s such as [[kaempferol]], [[quercitin]] and [[myricetin]] are often present. [[Ellagic acid]] has never been found in any of the genera or species analysed. Sugars are transported within the plants in the form of [[sucrose]]. [[C3 carbon fixation|C3 photosynthesis]] has been found in a wide variety of genera.<ref name="Watson" /> The family has also evolved a unique chemistry. Many legumes contain toxic<ref>{{Cite book|last=Taylor|first=Ronald J.|url=https://www.worldcat.org/oclc/25708726|title=Sagebrush Country: A Wildflower Sanctuary|publisher=Mountain Press Pub. Co|year=1994|isbn=0-87842-280-3|edition=rev.|location=Missoula, MT|pages=100|language=en|oclc=25708726|orig-year=1992}}</ref> and indigestible substances, [[antinutrient]]s, which may be removed through various processing methods. [[Pterocarpan]]s are a class of molecules (derivatives of [[isoflavonoid]]s) found only in the Fabaceae. [[Forisome]] proteins are found in the sieve tubes of Fabaceae; uniquely they are not dependent on [[Adenosine triphosphate|ADT]].

== Evolution, phylogeny and taxonomy ==
=== Evolution ===
The order Fabales contains around 7.3% of eudicot species and the greatest part of this diversity is contained in just one of the four families that the order contains: Fabaceae. This clade also includes the families [[Polygalaceae]], [[Surianaceae]] and [[Quillajaceae]] and its origins date back 94 to 89 million years, although it started its diversification 79 to 74 million years ago.<ref name="Stevens 2001" /> The Fabaceae diversified during the [[Paleogene]] to become a ubiquitous part of the modern earth's [[Biota (ecology)|biota]], along with many other families belonging to the flowering plants.<ref name="Lewis" /><ref name="Herendeen92">Herendeen, P. S., W. L. Crepet, and D. L. Dilcher. 1992. The fossil history of the Leguminosae: phylogenetic and biogeographic implications. Pages 303 – 316 in Advances in Legume Systematics, part 4, the fossil record (P. S. Herendeen and D .L. Dilcher, eds). Royal Botanic Gardens, Kew, UK.</ref>

The Fabaceae have an abundant and diverse [[fossil]] record, especially for the [[Tertiary]] period. Fossils of flowers, fruit, leaves, wood and [[pollen]] from this period have been found in numerous locations.<ref>{{cite journal|last1=Crepet|first1=W. L.|last2=Taylor|first2=D. W.|title=The Diversification of the Leguminosae: First Fossil Evidence of the Mimosoideae and Papilionoideae|journal=Science|volume=228|issue=4703|year=1985|pages=1087–1089|issn=0036-8075|doi=10.1126/science.228.4703.1087|pmid=17737903|bibcode=1985Sci...228.1087C|s2cid=19601874}}</ref><ref name="Crepet86">{{cite journal|author1=Crepet, W. L. |author2=D. W. Taylor |year=1986|title= Primitive mimosoid flowers from the Palaeocene-Eocene and their systematic and evolutionary implications.|journal= American Journal of Botany |volume=73|issue=4|pages=548–563|jstor=2444261|doi=10.2307/2444261}}</ref><ref name="Crepet92">Crepet, W. L., and P. S. Herendeen. 1992. Papilionoid flowers from the early Eocene of south eastern North America. Pages 43–55 in Advances in Legume Systematics, part 4, the fossil record (P. S. Herendeen and D. L. Dilcher, eds.). Royal Botanic Gardens, Kew, UK.</ref><ref name=autogenerated2>Herendeen, P. S. 1992. The fossil history of Leguminosae from the Eocene of south eastern North America. Pages 85-160 in Advances in Legume Systematics, part 4, the fossil record (Herendeen, P. S., and D. L. Dilcher, eds.). Royal Botanic Gardens, Kew, UK.</ref><ref name="Herendeen01">Herendeen, P. S. 2001. The fossil record of the Leguminosae: recent advances. In Legumes Down Under: the Fourth International Legume conference, Abstracts, 34–35. Australian National University, Canberra, Australia.</ref><ref name=autogenerated3>Herendeen, P. S., and S. Wing. 2001. Papilionoid legume fruits and leaves from the Palaeocene of north western Wyoming. Botany 2001 Abstracts, published by Botanical Society of America (http://www.botany2001.org/).</ref><ref name="Wing">Wing, S. L., F. Herrera, and C. Jaramillo. 2004. A Palaeocene flora from the Cerrajón Formation, Guajíra Peninsula, north eastern Colombia. Pages 146-147 in VII International Organization of Paleobotany Conference Abstracts (21–26 March). Museo Egidio Feruglio, Trelew, Argentina.</ref> The earliest fossils that can be definitively assigned to the Fabaceae appeared in the early [[Palaeocene]] (approximately 65 million years ago).<ref>{{Cite journal |last1=Herendeen |first1=Patrick S. |last2=Cardoso |first2=Domingos B. O. S. |last3=Herrera |first3=Fabiany |last4=Wing |first4=Scott L. |date=January 2022 |title=Fossil papilionoids of the Bowdichia clade (Leguminosae) from the Paleogene of North America |journal=American Journal of Botany |language=en |volume=109 |issue=1 |pages=130–150 |doi=10.1002/ajb2.1808 |issn=0002-9122 |pmc=9306462 |pmid=35014023}}</ref> Representatives of the 3 sub-families traditionally recognised as being members of the Fabaceae – Cesalpinioideae, Papilionoideae and Mimosoideae{{Snd}}as well as members of the large clades within these sub-families{{Snd}}such as the genistoides{{Snd}}have been found in periods later, starting between 55 and 50 million years ago.<ref name="Herendeen92" /> In fact, a wide variety of taxa representing the main lineages in the Fabaceae have been found in the fossil record dating from the middle to the late [[Eocene]], suggesting that the majority of the modern Fabaceae groups were already present and that a broad diversification occurred during this period.<ref name="Herendeen92" /> Therefore, the Fabaceae started their diversification approximately 60 million years ago and the most important clades separated 50 million years ago.<ref name="Bruneau2008b">Bruneau, A., Lewis, G. P., Herendeen, P. S., Schrire, B., & Mercure, M. 2008b. Biogeographic patterns in early-diverging clades of the Leguminosae. Pp. 98–99, in Botany 2008. Botany without Borders. [Botanical Society of America, Abstracts.]</ref> The age of the main Cesalpinioideae clades have been estimated as between 56 and 34 million years and the basal group of the Mimosoideae as 44 ± 2.6 million years.<ref name="Bruneau2008a">{{cite journal |author1=Bruneau, A. |author2=Mercure, M. |author3=Lewis, G. P. |author4= Herendeen, P. S. |name-list-style=amp |year=2008 |title=Phylogenetic patterns and diversification in the caesalpinioid legumes |journal=Canadian Journal of Botany | volume=86 |issue=7 |pages=697–718 |doi=10.1139/B08-058}}</ref><ref name=autogenerated1>{{cite journal | author=Lavin, M., Herendeen, P. S., y Wojciechowski, M. F. |year=2005 |title=Evolutionary Rates Analysis of Leguminosae Implicates a Rapid Diversification of Lineages during the Tertiary |journal=Systematic Biology |volume=54 |issue=4 |pages=575–594 |doi=10.1080/10635150590947131 |pmid=16085576 |last2=Herendeen |last3=Wojciechowski|doi-access=free }}</ref> The division between Mimosoideae and Faboideae is dated as occurring between 59 and 34 million years ago and the basal group of the Faboideae as 58.6 ± 0.2 million years ago.<ref name="Wikström">{{cite journal|last1=Wikstrom|first1=N.|last2=Savolainen|first2=V.|last3=Chase|first3=M. W.|title=Evolution of the angiosperms: calibrating the family tree|journal=Proceedings of the Royal Society B: Biological Sciences|date=2001|volume=268|issue=1482|pages=2211–2220|doi=10.1098/rspb.2001.1782|pmid=11674868|pmc=1088868}}</ref> It has been possible to date the divergence of some of the groups within the Faboideae, even though diversification within each genus was relatively recent. For instance, ''[[Astragalus (plant)|Astragalus]]'' separated from the ''[[Oxytropis]]'' 16 to 12 million years ago. In addition, the separation of the [[aneuploidy|aneuploid]] species of ''Neoastragalus'' started 4 million years ago. ''[[Inga]]'', another genus of the Papilionoideae with approximately 350 species, seems to have diverged in the last 2 million years.<ref name="Wojciechowski03">Wojciechowski, M. F. 2003. Reconstructing the phylogeny of legumes (Leguminosae): An early 21st century perspective. Pp. 5–35, in Klitgaard, B. B. & Bruneau, A. (eds), Advances in Legume Systematics, Part 10, Higher Level Systematics. Royal Botanic Gardens, Kew.</ref><ref name="Wojciechowski04">{{cite journal|last1=Wojciechowski|first1=M. F.|title=Astragalus (Fabaceae): A molecular phylogenetic perspective|journal=Brittonia|date=2005|volume=57|issue=4|pages=382–396|doi=10.1663/0007-196X(2005)057[0382:AFAMPP]2.0.CO;2|jstor=4098954|s2cid=21645067 }}</ref><ref name="Wojciechowski93">{{cite journal|last1=Wojciechowski|first1=M. F.|last2=Sanderson|first2=M. J.|last3=Baldwin|first3=B. G.|last4=Donoghue|first4=M. J.|date=1993|title=Monophyly of aneuploid ''Astragalus'': Evidence from nuclear ribosomal DNA internal transcribed spacer sequences|journal=American Journal of Botany|volume=80|issue=6|pages=711–722|jstor=2445441|doi=10.2307/2445441}}</ref><ref name="Wojciechowski06">Wojciechowski, Martin F., Johanna Mahn, and Bruce Jones. 2006. Fabaceae. legumes. Version 14 June 2006. [http://tolweb.org/Fabaceae/21093/2006.06.14 The Tree of Life Web Project], http://tolweb.org/</ref>

It has been suggested, based on fossil and phylogenetic evidence, that legumes originally evolved in arid and/or semi-arid regions along the [[Tethys Ocean|Tethys seaway]] during the [[Palaeogene]] Period.<ref name="Schrire2">{{cite book | last1 = Schrire | first1 = B. D. | last2 = Lewis | first2 = G. P. | last3 = Lavin | first3 = M. | editor1-first = G | editor1-last = Lewis | editor2-first = G. | editor2-last = Schrire | editor3-first = B. | editor3-last = Mackinder | editor4-first = M. | editor4-last = Lock | title = Legumes of the world | chapter-url = http://www.kewbooks.com/asps/ShowDetails.asp?id=506 | year = 2005 | publisher = Royal Botanic Gardens | location = Kew, England | isbn = 978-1-900347-80-8 | pages = 21–54 | chapter = Biogeography of the Leguminosae | access-date = 8 July 2010 | archive-date = 2 February 2014 | archive-url = https://web.archive.org/web/20140202160032/http://www.kewbooks.com/asps/ShowDetails.asp?id=506 | url-status = dead }}</ref><ref name="Schrire1">{{cite book | last1 = Schrire | first1 = B. D. | last2 = Lavin | first2 = M. | last3 = Lewis | first3 = G. P. | editor1-first = I | editor1-last = Friis | editor2-first = H. | editor2-last = Balslev | title = Plant diversity and complexity patterns: local, regional and global dimensions | series = Biologiske Skrifter | volume = 55 | year = 2005 | publisher = Special-Trykkeriet Viborg A/S | location = Viborg, Denmark | isbn = 978-87-7304-304-2 | pages = 375–422 | chapter = Global distribution patterns of the Leguminosae: insights from recent phylogenies}}</ref> However, others contend that [[Africa]] (or even the [[Americas]]) cannot yet be ruled out as the origin of the family.<ref>{{cite journal |doi=10.1111/j.1095-8339.2010.01044.x |title=Detarieae ''sensu lato'' (Fabaceae) from the Late Oligocene (27.23 Ma) Guang River flora of north-western Ethiopia |year=2010 |last1=Pan |first1=Aaron D. |last2=Jacobs |first2=Bonnie F. |last3=Herendeen |first3=Patrick S. |journal=Botanical Journal of the Linnean Society |volume=163 |pages=44–54|doi-access=free }}</ref><ref>{{cite journal |doi=10.1104/pp.102.018150 |title=The Rest of the Iceberg. Legume Diversity and Evolution in a Phylogenetic Context |year=2003 |last1=Doyle |first1=J. J. |journal=Plant Physiology |volume=131 |issue=3 |pages=900–10 |pmid=12644643 |last2=Luckow |first2=MA |pmc=1540290}}</ref>

The current hypothesis about the evolution of the genes needed for nodulation is that they were recruited from other pathways after a polyploidy event.<ref>{{cite journal |doi=10.1007/s00018-011-0651-4 |title=Function and evolution of nodulation genes in legumes |year=2011 |last1=Yokota |first1=Keisuke |last2=Hayashi |first2=Makoto |s2cid=13154916 |journal=Cellular and Molecular Life Sciences |volume=68 |issue=8 |pages=1341–51 |pmid=21380559|pmc=11114672 }}</ref> Several different pathways have been implicated as donating duplicated genes to the pathways need for nodulation. The main donors to the pathway were the genes associated with the arbuscular mycorrhiza symbiosis genes, the pollen tube formation genes and the haemoglobin genes. One of the main genes shown to be shared between the arbuscular mycorrhiza pathway and the nodulation pathway is SYMRK and it is involved in the plant-bacterial recognition.<ref>{{cite journal |doi=10.1371/journal.pbio.0060068 |title=Functional Adaptation of a Plant Receptor- Kinase Paved the Way for the Evolution of Intracellular Root Symbioses with Bacteria |year=2008 |last1=Markmann |first1=Katharina |last2=Giczey |first2=Gábor |last3=Parniske |first3=Martin |journal=PLOS Biology |volume=6 |issue=3 |pages=e68 |pmid=18318603 |pmc=2270324 |doi-access=free }}</ref> The pollen tube growth is similar to the infection thread development in that infection threads grow in a polar manner that is similar to a pollen tubes polar growth towards the ovules. Both pathways include the same type of enzymes, pectin-degrading cell wall enzymes.<ref>{{cite journal |doi=10.1111/j.1365-313X.2004.02155.x |title=From pollen tubes to infection threads: Recruitment of Medicago floral pectic genes for symbiosis |year=2004 |last1=Rodríguez-Llorente |first1=Ignacio D. |last2=Pérez-Hormaeche |first2=Javier |last3=Mounadi |first3=Kaoutar El |last4=Dary |first4=Mohammed |last5=Caviedes |first5=Miguel A. |last6=Cosson |first6=Viviane |last7=Kondorosi |first7=Adam |last8=Ratet |first8=Pascal |last9=Palomares |first9=Antonio J. |journal=The Plant Journal |volume=39 |issue=4 |pages=587–98 |pmid=15272876 |doi-access=free }}</ref> The enzymes needed to reduce nitrogen, nitrogenases, require a substantial input of ATP but at the same time are sensitive to free oxygen. To meet the requirements of this paradoxical situation, the plants express a type of haemoglobin called leghaemoglobin that is believed to be recruited after a duplication event.<ref>{{cite journal |doi=10.1016/j.cub.2005.03.007 |title=Legume Haemoglobins: Symbiotic Nitrogen Fixation Needs Bloody Nodules |year=2005 |last1=Downie |first1=J. Allan |journal=Current Biology |volume=15 |issue=6 |pages=R196–8 |pmid=15797009|s2cid=17152647 |doi-access=free |bibcode=2005CBio...15.R196D }}</ref> These three genetic pathways are believed to be part of a gene duplication event then recruited to work in nodulation.

=== Phylogeny and taxonomy ===
==== Phylogeny ====
The [[Phylogenetics|phylogeny]] of the legumes has been the object of many studies by research groups from around the world. These studies have used morphology, [[DNA]] data (the [[chloroplast]] [[intron]] ''trnL'', the chloroplast [[gene]]s ''rbcL'' and ''matK'', or the ribosomal spacers  ''ITS'') and [[Cladistics|cladistic analysis]] in order to investigate the relationships between the family's different lineages. Fabaceae is consistently recovered as [[Monophyly|monophyletic]].<ref name="tolweb">{{cite web | url = http://tolweb.org/Fabaceae/21093/2006.06.14 | title = Fabaceae |author1=Martin F. Wojciechowski |author2=Johanna Mahn |author3=Bruce Jones | year = 2006 | work = The Tree of Life Web Project }}</ref> The studies further confirmed that the traditional subfamilies Mimosoideae and Papilionoideae were each [[Monophyly|monophyletic]] but both were nested within the paraphyletic subfamily Caesalpinioideae.<ref name="wojciechowski2004">{{cite journal | doi = 10.3732/ajb.91.11.1846 | title = A phylogeny of legumes (Leguminosae) based on analysis of the plastid matK gene resolves many well-supported sub clades within the family | year = 2014 |author1=Wojciechowski, M. F. |author2=Lavin, M. |author3=Sanderson, M. J. | journal = American Journal of Botany | volume = 91 | pages = 1846–62 | issue = 11 | pmid = 21652332 | doi-access = free }}</ref><ref name="tolweb" /> All the different approaches yielded similar results regarding the relationships between the family's main clades.<ref name="Stevens 2001" /><ref name="Käss">{{cite journal |vauthors=Käss E, Wink M | year = 1996 | title = Molecular evolution of the Leguminosae: phylogeny of the three subfamilies based on ''rbcL'' sequences | journal = Biochemical Systematics and Ecology | volume = 24 | issue = 5 | pages = 365–378 | doi = 10.1016/0305-1978(96)00032-4 | bibcode = 1996BioSE..24..365K }}</ref><ref name="Käss2">{{cite journal |vauthors=Käss E, Wink M | year = 1997 | title = Phylogenetic relationships in the Papilionoideae (Family Leguminosae) based on nucleotide sequences of cpDNA (''rbcL'') and ncDNA (ITS1 and 2) | journal = [[Molecular Phylogenetics and Evolution|Mol. Phylogenet. Evol.]] | volume = 8 | issue = 1 | pages = 65–88 | pmid = 9242596 | doi = 10.1006/mpev.1997.0410 | bibcode = 1997MolPE...8...65K }}</ref><ref name="Doyle">{{cite journal |vauthors=Doyle JJ, Doyle JL, Ballenger JA, Dickson EE, Kajita T, Ohashi H | year = 1997 | title = A phylogeny of the chloroplast gene ''rbcL'' in the Leguminosae: taxonomic correlations and insights into the evolution of nodulation | journal = [[American Journal of Botany|Am. J. Bot.]] | volume = 84 | issue = 4 | pages = 541–554 | pmid = 21708606 | doi = 10.2307/2446030| jstor = 2446030 | doi-access = free }}</ref><ref name="Lavin">{{cite journal |vauthors=Lavin M, Doyle JJ, Palmer JD | year = 1990 | title = Evolutionary significance of the loss of the chloroplast-DNA inverted repeat in the Leguminosae subfamily Papilionoideae | journal = [[Evolution (journal)|Evolution]] | volume = 44 | issue = 2 | pages = 390–402 | jstor = 2409416 | doi=10.2307/2409416| pmid = 28564377 | hdl = 2027.42/137404 | url = https://deepblue.lib.umich.edu/bitstream/2027.42/137404/1/evo05207.pdf | hdl-access = free }}</ref><ref name="Sanderson">{{cite journal |vauthors=Sanderson MJ, Wojciechowski MF | year = 1996 | title = Diversification rates in a temperate legume clade: are there "so many species" of ''Astragalus'' (Fabaceae)? | journal = [[American Journal of Botany|Am. J. Bot.]] | volume = 83 | issue = 11 | pages = 1488–1502 | jstor = 2446103 | doi=10.2307/2446103}}</ref><ref name="Chappill">{{cite book | author = Chappill JA. | year = 1995 | chapter = Cladistic analysis of the Leguminosae: the development of an explicit hypothesis | pages = 1–10 | title = Advances in Legume Systematics, Part 7: Phylogeny |veditors=Crisp MD, Doyle JJ | publisher = Royal Botanic Gardens, Kew, UK | isbn = 9780947643799}}</ref><ref>{{cite journal |vauthors=Bruneau A, Mercure M, Lewis GP, Herendeen PS | year = 2008 |title = Phylogenetic patterns and diversification in the caesalpinioid legumes | journal = [[Botany (journal)|Botany]] | volume = 86 | issue = 7 | pages = 697–718 | doi = 10.1139/B08-058}}</ref><ref>{{cite journal |vauthors=Cardoso D, Pennington RT, de Queiroz LP, Boatwright JS, Van Wykd BE, Wojciechowskie MF, Lavin M | year = 2013 | title = Reconstructing the deep-branching relationships of the papilionoid legumes | journal = S. Afr. J. Bot. | volume = 89 | pages = 58–75 | doi = 10.1016/j.sajb.2013.05.001| doi-access = free | hdl = 10566/3193 | hdl-access = free }}</ref> Following extensive discussion in the legume phylogenetics community, the Legume Phylogeny Working Group reclassified Fabaceae into six subfamilies, which necessitated the segregation of four new subfamilies from Caesalpinioideae and merging Caesapinioideae ''sensu stricto'' with the former subfamily Mimosoideae.<ref name="6subfamilies">{{cite journal | author = The Legume Phylogeny Working Group (LPWG). | year = 2017 | title = A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny | journal = [[Taxon (journal)|Taxon]] | volume = 66 | issue = 1 | pages = 44–77 | doi = 10.12705/661.3| doi-access = free | hdl = 10568/90658 | hdl-access = free }}</ref><ref>{{cite journal |vauthors=Koenen EJ, Ojeda DI, Steeves R, Migliore J, Bakker FT, Wieringa JJ, Kidner C, Hardy OJ, Pennington RT, Bruneau A, Hughes CE | year = 2019 | title = Large-scale genomic sequence data resolve the deepest divergences in the legume phylogeny and support a near-simultaneous evolutionary origin of all six subfamilies | journal = New Phytologist | volume = 225 | issue = 3 | pages = 1355–1369 | doi = 10.1111/nph.16290| pmid = 31665814 | pmc = 6972672 | doi-access = free }}</ref> The exact branching order of the different subfamilies is still unresolved.<ref>{{cite journal |vauthors=Zhang R, Wang YH, Jin JJ, Stull GW, Bruneau A, Cardoso D, De Queiroz LP, Moore MJ, Zhang SD, Chen SY, Wang J, Li DZ, Yi TS | year = 2020 | title = Exploration of Plastid Phylogenomic Conflict Yields New Insights into the Deep Relationships of Leguminosae | journal = Syst. Biol. | volume = 69 | issue = 4 | pages = 613–622 | doi = 10.1093/sysbio/syaa013 | pmid = 32065640 | pmc = 7302050 }}</ref>

{{Clade| style=line-height:75%;
|label1=[[Fabales]]
|1={{clade
  |1=[[Polygalaceae]] ([[Outgroup (cladistics)|outgroup]])
  |2=[[Surianaceae]] (outgroup)
  |3={{clade
    |1=[[Quillajaceae]] (outgroup)
    |label2='''Fabaceae'''
    |2={{clade
      |1={{clade
        |1=[[Cercidoideae]]
        |2=[[Detarioideae]]
         }}
      |2={{clade
        |1=[[Duparquetioideae]]
        |2={{clade
          |1=[[Dialioideae]]
          |2={{clade
            |1=[[Caesalpinioideae]]
            |2=[[Faboideae]]
             }}
           }}
         }}
       }}
     }}
   }}
}}

==== Taxonomy ====
The Fabaceae are placed in the order [[Fabales]] according to most taxonomic systems, including the [[APG III system]].<ref name=APGIII2009 /> The family now includes six subfamilies:<ref name="6subfamilies"/>
* [[Cercidoideae]]: 12 genera and ~335 species. Mainly tropical. ''[[Bauhinia]]'', ''[[Cercis]]''.
* [[Detarioideae]]: 84 genera and ~760 species. Mainly tropical. ''[[Amherstia]]'', ''[[Detarium]]'', ''[[Tamarindus]]''.
* [[Duparquetioideae]]: 1 genus and 1 species. West and Central Africa. ''[[Duparquetia]]''.
* [[Dialioideae]]: 17 genera and ~85 species. Widespread throughout the tropics. ''[[Dialium]]''.
* [[Caesalpinioideae]]: 148 genera and ~4400 species. [[Pantropical]]. ''[[Caesalpinia]]'', ''[[Senna (plant)|Senna]]'', ''[[Mimosa]]'', ''[[Acacia]]''. Includes the former subfamily [[Mimosoideae]] (80 genera and ~3200 species; mostly tropical and warm temperate Asia and America).
* [[Faboideae]] (Papilionoideae<ref>NOTE: The subfamilial name Papilionoideae for Faboideae is approved by the [[International Code of Nomenclature for algae, fungi, and plants]], Article 19.8</ref>): 503 genera and ~14,000 species. [[Cosmopolitan distribution|Cosmopolitan]]. ''[[Astragalus (plant)|Astragalus]]'', ''[[Lupinus]]'', ''[[Pisum]]''.

== Ecology ==

=== Distribution and habitat ===
The Fabaceae have an essentially worldwide distribution, being found everywhere except Antarctica and the high Arctic.<ref name="Stevens 2001" /> The trees are often found in tropical regions, while the herbaceous plants and shrubs are predominant outside the tropics.<ref name="Watson" />

=== Biological nitrogen fixation ===
[[File:Vicia sepium10 ies.jpg|thumb| Roots of ''[[Vicia]]'' with white root nodules visible.]]
[[File:Cross-section through root nodule of (Vicia spec.).jpg|thumb| Cross-section through a root nodule of ''[[Vicia]]'' observed through a microscope.]]
[[Nitrogen fixation|Biological nitrogen fixation]] (BNF, performed by the organisms called [[diazotroph]]s) is a very old process that probably originated in the [[Archean]] eon when the primitive [[atmosphere]] lacked [[oxygen]].  It is only carried out by [[Euryarchaeota]] and just 6 of the more than 50 [[Phylum|phyla]] of [[bacteria]]. Some of these lineages co-evolved together with the [[flowering plant]]s establishing the molecular basis of a mutually beneficial [[symbiosis|symbiotic]] relationship. BNF is carried out in nodules that are mainly located in the root cortex, although they are occasionally located in the stem as in ''[[Sesbania rostrata]]''. The [[spermatophyte]]s that co-evolved with [[actinorhizal]] diazotrophs (''[[Frankia]]'') or with [[rhizobia]] to establish their symbiotic relationship belong to 11 families contained within the [[Rosidae]] [[clade]] (as established by the gene molecular phylogeny of ''rbcL'', a gene coding for part of the [[RuBisCO]] enzyme in the [[chloroplast]]). This grouping indicates that the predisposition for forming nodules probably only arose once in flowering plants and that it can be considered as an ancestral characteristic that has been conserved or lost in certain lineages. However, such a wide distribution of families and genera within this lineage indicates that nodulation had multiple origins. Of the 10 families within the Rosidae, 8 have nodules formed by [[actinomyces]] ([[Betulaceae]], [[Casuarinaceae]], [[Coriariaceae]], [[Datiscaceae]], [[Elaeagnaceae]], [[Myricaceae]], [[Rhamnaceae]] and [[Rosaceae]]), and the two remaining families, [[Ulmaceae]] and Fabaceae have nodules formed by rhizobia.<ref name="Looret">{{cite journal | last1 = Lloret | first1 = L. | last2 = Martínez-Romero | first2 = E. | year = 2005 | title = Evolución y filogenia de | url = http://www.medigraphic.com/espanol/e-htms/e-lamicro/e-mi2005/e-mi05-1_2/em-mi05-1_2f.htm | archive-url = https://archive.today/20130411080503/http://www.medigraphic.com/espanol/e-htms/e-lamicro/e-mi2005/e-mi05-1_2/em-mi05-1_2f.htm | url-status = dead | archive-date = 2013-04-11 | journal = Rhizobium | volume = 47 | issue = 1–2 | pages = 43–60 }}</ref><ref name="Sprent">Sprent, J. I. 2001. Nodulation in legumes. Royal Botanic Gardens, Kew, UK.</ref>

The rhizobia and their hosts must be able to recognize each other for nodule formation to commence. Rhizobia are specific to particular host species although a rhizobia species may often infect more than one host species. This means that one plant species may be infected by more than one species of bacteria. For example, nodules in ''[[Acacia senegal]]'' can contain seven species of rhizobia belonging to three different genera.  The most distinctive characteristics that allow rhizobia to be distinguished apart are the rapidity of their growth and the type of root nodule that they form with their host.<ref name="Sprent" /> Root nodules can be classified as being either indeterminate, cylindrical and often branched, and determinate, spherical with prominent lenticels. Indeterminate nodules are characteristic of legumes from temperate climates, while determinate nodules are commonly found in species from tropical or subtropical climates.<ref name="Sprent" />

Nodule formation is common throughout the Fabaceae. It is found in the majority of its members that only form an association with rhizobia, which in turn form an exclusive symbiosis with the Fabaceae (with the exception of ''Parasponia'', the only genus of the 18 Ulmaceae genera that is capable of forming nodules). Nodule formation is present in all the Fabaceae sub-families, although it is less common in the Caesalpinioideae. All types of nodule formation are present in the subfamily Papilionoideae:  indeterminate (with the [[meristem]] retained), determinate (without meristem) and the type included in ''Aeschynomene''. The latter two are thought to be the most modern and specialised type of nodule as they are only present in some lines of the subfamily Papilionoideae. Even though nodule formation is common in the two [[Monophyly|monophyletic]] subfamilies Papilionoideae and Mimosoideae they also contain species that do not form nodules. The presence or absence of nodule-forming species within the three sub-families indicates that nodule formation has arisen several times during the evolution of the Fabaceae and that this ability has been lost in some lineages. For example, within the genus ''Acacia'', a member of the Mimosoideae, ''A. pentagona'' does not form nodules, while other species of the same genus readily form nodules, as is the case for ''Acacia senegal'', which forms both rapidly and slow growing rhizobial nodules.

=== Chemical ecology ===
A large number of species within many genera of leguminous plants, e.g. ''[[Astragalus (plant)|Astragalus]]'', ''[[Coronilla]]'', ''[[Hippocrepis]]'', ''[[Indigofera]]'', ''[[Lotus (genus)|Lotus]]'', ''[[Securigera]]'' and ''[[Scorpiurus (plant)|Scorpiurus]]'', produce chemicals that derive from the compound 3-nitropropanoic acid (3-NPA, [[beta-nitropropionic acid]]). The free acid 3-NPA is an [[irreversible inhibitor]] of mitochondrial [[Cellular respiration|respiration]], and thus the compound inhibits the [[tricarboxylic acid cycle]]. This inhibition caused by 3-NPA is especially toxic to nerve cells and represents a very general toxic mechanism suggesting a profound ecological importance due to the big number of species producing this compound and its derivatives. A second and closely related class of secondary metabolites that occur in many species of leguminous plants is defined by isoxazolin-5-one derivatives. These compounds occur in particular together with 3-NPA and related derivatives at the same time in the same species, as found in ''Astragalus canadensis'' and ''Astragalus collinus''. 3-NPA and isoxazlin-5-one derivatives also occur in many species of leaf beetles (see [[defense in insects]]).<ref name=Becker>{{cite journal | author = Becker T.|display-authors=etal| year = 2017 | title = A tale of four kingdoms - isoxazolin-5-one- and 3-nitropropanoic acid-derived natural products | journal = Natural Product Reports | volume = 34 | issue = 4| pages = 343–360 | doi=10.1039/C6NP00122J| pmid = 28271107 | doi-access = free | hdl = 11858/00-001M-0000-002C-51D4-1 | hdl-access = free }}</ref>

== Economic and cultural importance ==
Legumes are economically and culturally important plants due to their extraordinary diversity and abundance, the wide variety of edible vegetables they represent and due to the variety of uses they can be put to: in horticulture and agriculture, as a food, for the compounds they contain that have medicinal uses and for the oil and fats they contain that have a variety of uses.<ref name="Allen">Allen, O. N., & E. K. Allen. 1981. The Leguminosae, A Source Book of Characteristics, Uses, and Nodulation. The University of Wisconsin Press, Madison, USA.</ref><ref name="Duke">Duke, J. A. 1992. Handbook of Legumes of Economic Importance. Plenum Press, New York, USA.</ref><ref name="Graham">{{cite journal | last1 = Graham | first1 = P. H. | last2 = Vance | first2 = C. P. | year = 2003 | title = Legumes: importance and constraints to greater use | journal = Plant Physiology | volume = 131 | issue = 3| pages = 872–877 | doi=10.1104/pp.017004| pmc = 1540286 | pmid=12644639}}</ref><ref name="Wojciechowski06b">Wojciechowski, M.F. 2006. [http://tolweb.org/notes/?note_id=3968 Agriculturally & Economically Important Legumes.]. Accessed 15 November 2008.</ref>

=== Food and forage ===
The [[bean#History|history of legumes]] is tied in closely with that of human civilization, appearing early in [[Asia]], the [[Americas]] (the [[common bean]], several varieties) and [[Europe]] (broad beans) by 6,000 [[Anno Domini|BCE]], where they became a staple, essential as a source of protein.

Their ability to [[nitrogen fixation|fix atmospheric nitrogen]] reduces [[fertilizer]] costs for farmers and gardeners who grow legumes, and means that legumes can be used in a [[crop rotation]] to replenish soil that has been depleted of [[nitrogen]]. Legume seeds and foliage have a comparatively higher [[protein]] content than non-legume materials, due to the additional nitrogen that legumes receive through the process. Legumes are commonly used as natural fertilizers. Some legume species perform [[hydraulic redistribution|hydraulic lift]], which makes them ideal for [[intercropping]].<ref>{{cite book | last = Sprent | first = Janet I. | url = http://www.sprentland.com/index.php?pr=Janet | title = Legume Nodulation: A Global Perspective | year = 2009 | publisher = Wiley-Blackwell | location = Ames, Iowa | isbn = 978-1-4051-8175-4 | page = 12 }} Preview available at [https://books.google.com/books?id=c-DeQ_wQr3MC&dq=legume+hydraulic+lift&pg=PR4 Google Books].</ref>

Farmed legumes can belong to numerous classes, including [[Fodder|forage]], [[cereal|grain]], blooms, pharmaceutical/industrial, fallow/green manure and timber species, with most commercially farmed species filling two or more roles simultaneously.

There are of two broad types of forage legumes. Some, like [[alfalfa]], [[clover]], [[vetch]], and ''[[Arachis]]'', are sown in [[pasture]] and grazed by livestock. Other forage legumes such as ''[[Leucaena]]'' or ''[[Albizia]]'' are woody shrub or tree species that are either broken down by livestock or regularly cut by humans to provide [[fodder]].

Grain legumes are cultivated for their [[seed]]s, and are also called [[pulse (legume)|pulses]]. The seeds are used for human and animal consumption or for the production of [[Vegetable fats and oils|oils]] for industrial uses. Grain legumes include both herbaceous plants like [[bean]]s, [[lentil]]s, [[lupin]]s, [[pea]]s and [[peanut]]s,<ref>The gene bank and breeding of grain legumes (lupine, vetch, soya and beah) / B.S. Kurlovich and S.I. Repyev (Eds.), - St. Petersburg, The N.I. Vavilov Institute of Plant Industry, 1995, 438p. - (Theoretical basis of plant breeding. V.111)</ref> and trees such as [[carob]], [[mesquite]] and [[tamarind]].

''[[Lathyrus tuberosus]]'', once extensively cultivated in Europe, forms tubers used for human consumption.<ref>{{Cite journal|last1=Hossaert-Palauqui|first1=M.|last2=Delbos|first2=M.|date=1983|title=Lathyrus tuberosus L. Biologie et perspectives d'amélioration|journal=Journal d'Agriculture Traditionnelle et de Botanique Appliquée|volume=30|issue=1|pages=49–58|doi=10.3406/jatba.1983.3887|issn=0183-5173|url=https://hal.science/hal-04454449 }}</ref><ref>{{Cite web|url=http://www.luontoportti.com/suomi/en/kukkakasvit/tuberous-pea|title=Tuberous Pea, Lathyrus tuberosus - Flowers - NatureGate|website=www.luontoportti.com|access-date=2019-07-28}}</ref>

Bloom legume species include species such as [[lupin]], which are farmed commercially for their blooms, and thus are popular in gardens worldwide. ''[[Laburnum]]'', ''[[Robinia]]'', ''[[Gleditsia]]'' (honey locust), ''[[Acacia]]'', ''[[Mimosa]]'', and ''[[Delonix]]'' are [[Ornamental plant|ornamental]] [[tree]]s and [[shrub]]s.

Industrial farmed legumes include ''[[Indigofera]]'', cultivated for the production of [[Indigo dye|indigo]], ''[[Acacia]]'', for [[gum arabic]], and ''[[Derris]]'', for the insecticide action of [[rotenone]], a compound it produces.

Fallow or [[green manure]] legume species are cultivated to be tilled back into the soil to exploit the high nitrogen levels found in most legumes. Numerous legumes are farmed for this purpose, including ''[[Leucaena]]'', ''[[Cyamopsis]]'' and ''[[Sesbania]]''.

Various legume species are farmed for timber production worldwide, including numerous ''[[Acacia]]'' species, ''[[Dalbergia]]'' species, and ''[[Castanospermum australe]]''.

Melliferous plants offer [[nectar]] to [[bee]]s and other insects to encourage them to carry pollen from the [[flower]]s of one plant to others thereby ensuring pollination. Many Fabaceae species are important sources of pollen and nectar for bees, including for honey production in the beekeeping industry. Example Fabaceae such as [[alfalfa]], and various clovers including [[Trifolium repens|white clover]] and [[Melilotus|sweet clover]], are important sources of nectar and honey for the [[Apis mellifera|Western honey bee]].<ref>{{Cite journal|title = Nectar and Pollen Plants|last1 = Oertel|first1 = E.|date = 1967|journal = US Dep. Agr. Handbook |volume = 335|pages = 10–16}}</ref>

=== Industrial uses ===

==== Natural gums ====
[[Natural gum]]s are vegetable exudates that are released as the result of damage to the plant such as that resulting from the attack of an insect or a natural or artificial cut. These exudates contain heterogeneous [[polysaccharide]]s formed of different sugars and usually containing [[uronic acid]]s. They form viscous colloidal solutions. There are different species that produce gums. The most important of these species belong to the Fabaceae. They are widely used in the pharmaceutical, cosmetic, food, and textile sectors. They also have interesting therapeutic properties; for example [[gum arabic]] is [[antitussive]] and [[anti-inflammatory]].{{Medical citation needed|date=March 2024}} The most well known gums are [[tragacanth]] (''Astragalus gummifer''), gum arabic (''[[Acacia senegal]]'') and [[guar gum]] (''[[Cyamopsis tetragonoloba]]'').<ref name=autogenerated4>Kuklinski, C. 2000. Farmacognosia : estudio de las drogas y sustancias medicamentosas de origen natural. Ediciones Omega, Barcelona. {{ISBN|84-282-1191-4}}</ref>

=== Dyes ===
[[File:Indigo plant extract sample.jpg|thumb|[[Indigo dye|Indigo]] colorant]]
Several species of Fabaceae are used to produce dyes. The heartwood of logwood, ''[[Haematoxylon campechianum]]'', is used to produce red and purple dyes. The [[Histology|histological]] stain called [[haematoxylin]] is produced from this species. The wood of the Brazilwood tree (''[[Caesalpinia echinata]]'') is also used to produce a red or purple dye. The Madras thorn (''[[Pithecellobium dulce]]'') has reddish fruit that are used to produce a yellow dye.<ref name="MARQUEZ">Marquez, A. C., Lara, O.F., Esquivel, R. B. & Mata, E. R. 1999. Composición, usos y actividad biológica: Plantas medicinales de México II. UNAM. First edition. México, D.F.</ref> Indigo dye is extracted from the indigo plant ''[[Indigofera tinctoria]]'' that is native to Asia. In Central and South America dyes are produced from two species in the same genus: indigo and [[Maya blue]] from ''[[Indigofera suffruticosa]]'' and Natal indigo from ''[[Indigofera arrecta]]''. Yellow dyes are extracted from ''[[Butea monosperma]]'', commonly called flame of the forest and from dyer's greenweed, (''[[Genista tinctoria]]'').<ref name=botanical>{{cite web|url= http://botanical.com/botanical/mgmh/b/brodye72.html|title=Broom, Dyer's|access-date=September 1, 2020}}</ref>

=== Ornamentals ===
[[File:Erythrina crista-galli 08 ies.jpg|thumb|The Cockspur Coral Tree ''[[Erythrina crista-galli]]'' is one of many Fabaceae used as [[ornamental plant]]s. In addition, it is the [[National Flower of Argentina]] and [[Uruguay]].]]
Legumes have been used as ornamental plants throughout the world for many centuries. Their vast diversity of heights, shapes, foliage and flower colour means that this family is commonly used in the design and planting of everything from small gardens to large parks.<ref name="uno" /> The following is a list of the main ornamental legume species, listed by subfamily.
* Subfamily Caesalpinioideae: ''[[Bauhinia forficata]]'', ''[[Caesalpinia gilliesii]]'', ''[[Caesalpinia spinosa]]'', ''[[Ceratonia siliqua]]'', ''[[Cercis siliquastrum]]'', ''[[Gleditsia triacanthos]]'', ''[[Gymnocladus dioica]]'', ''[[Parkinsonia aculeata]]'', ''[[Senna multiglandulosa]]''.<ref name="Macaya">Macaya J. 1999. [http://www.chlorischile.cl/ Leguminosas arbóreas y arbustivas cultivadas en Chile.] Chloris Chilensis Año 2. Nº1.</ref>
* Subfamily Mimosoideae: ''[[Acacia caven]]'', ''[[Acacia cultriformis]]'', ''[[Acacia dealbata]]'', ''[[Acacia karroo]]'', ''[[Acacia longifolia]]'', ''[[Acacia melanoxylon]]'', ''[[Acacia paradoxa]]'', ''[[Acacia retinodes]]'', ''[[Acacia saligna]]'', ''[[Acacia verticillata]]'', ''[[Acacia visco]]'', ''[[Albizzia julibrissin]]'', ''[[Calliandra tweediei]]'', ''[[Paraserianthes lophantha]]'', ''[[Prosopis chilensis]]''.<ref name="Macaya" />
* Subfamily Faboideae: ''[[Clianthus puniceus]]'', ''[[Cytisus scoparius]]'', ''[[Erythrina crista-galli]]'', ''[[Erythrina falcata]]'','' [[Laburnum anagyroides]]'', ''[[Lotus peliorhynchus]]'', ''[[Lupinus arboreus]]'', ''[[Lupinus polyphyllus]]'', ''[[Otholobium glandulosum]]'','' [[Retama monosperma]]'', ''[[Robinia hispida]]'', ''[[Robinia luxurians]]'', ''[[Robinia pseudoacacia]]'', ''[[Styphnolobium japonicum|Sophora japonica]]'', ''[[Sophora macnabiana]]'','' [[Sophora macrocarpa]]'', ''[[Spartium junceum]]'', ''[[Teline monspessulana]]'', ''[[Tipuana tipu]]'', ''[[Wisteria sinensis]]''.<ref name="Macaya" />

== Emblematic Fabaceae ==
* The Cockspur Coral Tree (''[[Erythrina crista-galli]]''), is the [[National Flower of Argentina]] and [[Uruguay]].<ref>Ministerio de Educación de la Nación. Subsecretaría de Coordinación Administrativa. [http://www.me.gov.ar/efeme/ceibo/index.html Día de la Flor Nacional "El Ceibo"] {{Webarchive|url=https://web.archive.org/web/20160112082543/http://www.me.gov.ar/efeme/ceibo/index.html |date=12 January 2016 }}. Efemérides Culturales Argentinas. Consulted 3 March 2010.</ref>
* The Elephant ear tree (''[[Enterolobium cyclocarpum]]'') is the national tree of [[Costa Rica]], by Executive Order of 31 August 1959.<ref name="Gilbert">Gilbert Vargas Ulate. 1997. Geografía turística de Costa Rica. EUNED, 180 p. {{ISBN|9977-64-900-6}}, 9789977649009.</ref>
* The Brazilwood tree (''[[Caesalpinia echinata]]'') has been the national tree of [[Brazil]] since 1978.<ref name="LEI">"Lei Nº 6.607, de 7 de dezembro de 1978. O Presidente da República, faço saber que o Congresso Nacional decreta e eu sanciono a seguinte Lei:
Art. 1º- É declarada Árvore Nacional a leguminosa denominada Pau-Brasil (''Caesalpinia echinata'', Lam), cuja festa será comemorada, anualmente, quando o Ministério da Educação e Cultura promoverá campanha elucidativa sobre a relevância daquela espécie vegetal na História do Brasil."</ref>
* The Golden wattle ''[[Acacia pycnantha]]'' is [[Australia]]'s national flower.<ref name=boden>{{cite journal| author=Boden, Anne| year=1985| title=Golden Wattle: Floral Emblem of Australia | format=http | journal=Australian National Botanic Gardens | url=http://www.anbg.gov.au/emblems/aust.emblem.html | access-date=8 October 2008}}</ref>
* The Hong Kong Orchid tree ''[[Bauhinia blakeana]]'' is the national flower of [[Hong Kong]].<ref name=Williams>{{cite journal| author=Williams, Martin  | year=1999| title=Golden Enigmatic Beauty| format=http | journal=Bahuninia| url=http://martinwilliams.tripod.com/hkwildstars/bauhinia.html| access-date=8 October 2008}}</ref>

== Image gallery ==
<gallery>
File:MG 7005.jpg|''[[Acacia baileyana]]'' (Wattle)
File:Starr 050419-0368 Alysicarpus vaginalis.jpg|[[Loment]]s of ''[[Alysicarpus]] vaginalis''
File:CalliandraEmarginata.JPG|''[[Calliandra]] emarginata''
File:Cassia_leptophylla_tree.jpg|''[[Cassia leptophylla]]'' tree
File:Desmodium gangeticum W2 IMG 2776.jpg|''[[Pleurolobus gangeticus]]''
File:Sickle Bush (Dichrostachys cinerea) in Hyderabad, AP W2 IMG 9903.jpg|''[[Dichrostachys cinerea]]'' Sickle Bush
File:Royal_Ponciana.jpg|''[[Delonix regia]]'' tree
File:Indigofera-gerardiana.JPG|''[[Indigofera gerardiana]]''
File:Lathyrus odoratus 5 ies.jpg|Tendrils of ''[[Lathyrus odoratus]]'' (Sweet pea)
File:Arboreus infl.jpg|Inflorescence of ''[[Lupinus arboreus]]'' (Yellow bush lupin)
File:Blauwschokker Kapucijner rijserwt Pisum sativum.jpg|''[[Pisum sativum]]'' (Peas); note the leaf-like stipules
File:Smithia conferta W IMG 2191.jpg|''[[Smithia conferta]]''
File:Trifolium repens in Kullu distt W IMG 6655.jpg| ''[[Trifolium repens]]'' in [[Kullu]] District of [[Himachal Pradesh]], [[India]].
File:Vicia cassubica W.jpg|''[[Kashubian vetch]]'' – [[Kashubia]]
File:Zornia gibbosa W IMG 1666.jpg|''[[Zornia gibbosa]]''
File:Cytisus scoparius2.jpg|''[[Cytisus scoparius]]'' (Scotch broom)
File:Senna_pendula6.jpg|''[[Senna pendula]]'' (Easter cassia)
File:Fabaceae Stipulate Lotus Hosackia stipularis.jpg|''[[Hosackia stipularis]]'' (Stipulate Lotus)
File:Fabaceae lupinus nanus sky lupine.jpg|''[[Lupinus manus]]'' (Sky Lupine)
File:Starr_071024-0313_Vigna_caracalla.jpg|''[[Vigna caracalla]]'' (snail vine) flowers
File:Fabaceae Arroyo lupine succulent lupine lupinus succulentus.jpg|''[[Lupinus succulentus]]'' (Arroyo Lupine Succulent)
File:Fabaceae harlequin lupine lupinus stiversii.jpg|''[[Lupinus stiversii]]'' (Harlequin Lupine)
File:Virgilia_tree_Keurboom_-_Cape_Town_2.JPG|''[[Virgilia oroboides]]'' (Cape lilac) mauve flowers
File:Vicia grandiflora. jpg.jpg|''[[Vicia grandiflora]]''
</gallery>

== References ==
{{Reflist|30em}}

== External links ==
{{Wikispecies}}
{{Commons category|Fabaceae}}
{{Americana Poster|Leguminosæ}}
* [http://www.mobot.org/mobot/research/APweb/orders/fabalesweb.htm#Fabaceae Fabaceae] at the [http://www.mobot.org/mobot/research/APweb/welcome.html ''Angiosperm Phylogeny Website'']
* [https://ildis.org/LegumeWeb/ LegumeWeb Database] at the [http://www.ildis.org/ ''International Legume Database & Information Service (ILDIS)'']

{{Angiosperm families}}
{{Taxonbar|from1=Q44448|from2=Q14856098}}
{{Authority control}}

[[Category:Fabaceae| ]]
[[Category:Nitrogen cycle]]
[[Category:Extant Paleocene first appearances]]
[[Category:Rosid families]]
[[Category:Soil improvers]]