The inverted repeat-lacking clade (IRLC) is a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of the

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

subfamily

Faboideae The Faboideae are a subfamily of the flowering plant family Fabaceae or Leguminosae. An acceptable alternative name for the subfamily is Papilionoideae, or Papilionaceae when this group of plants is treated as a family. This subfamily is wide ...

(or Papilionaceae). Faboideae includes the majority of agriculturally-cultivated

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

s. The name of this clade is informal and is not assumed to have any particular

taxonomic rank In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family (biology), family, order (biology), order, class (b ...

like the names authorized by the

ICBN The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

or the ICPN. The clade is characterized by the loss of one of the two 25-kb inverted repeats in the plastid genome that are found in most land plants. It is consistently resolved in

molecular phylogenies Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

. The clade is predicted to have diverged from the other legume lineages 39.0±2.4 million years ago (in the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

). It includes several large, temperate genera such as ''

Astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

'' L., ''

Hedysarum ''Hedysarum'' (sweetvetch) is a genus of the botanical family Fabaceae, consisting of about 200 species of annual or perennial herbs in Asia, Europe, North Africa, and North America. Description Species within genus ''Hedysarum'' may be herb ...

'' L., ''

Medicago ''Medicago'' is a genus of flowering plants, commonly known as medick or burclover, in the legume family (Fabaceae). It contains at least 87 species and is distributed mainly around the Mediterranean basin. The best-known member of the genus is ...

'' L., ''

Oxytropis ''Oxytropis'' is a genus of plants in the legume family. It is one of three genera of plants known as locoweeds, and are notorious for being toxic to grazing animals. The other locoweed genus is the closely related ''Astragalus''. There are abo ...

'' DC., '' Swainsona'' Salisb., and ''

Trifolium Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus h ...

'' L..

Description

This clade is composed of five traditional tribes ( Cicereae Alef.,

Fabeae The tribe (biology), tribe Fabeae (sometimes referred to as "Vicieae") is one of the subdivisions of the plant family (biology), family Fabaceae. It is included within the Inverted repeat-lacking clade (IRLC). Five genus, genera are included: * ' ...

Rchb.,

Galegeae Galegeae is a tribe in the flowering plant family Fabaceae, subfamily Faboideae. The tribe is found mostly in the northern hemisphere, but can also be found in Australia, Africa, and South America. Recent molecular phylogenetic work has determine ...

Dumort.,

Hedysareae Hedysareae is a tribe of plants in the subfamily Faboideae. Hedysareae species have loments, a type of modified legume that breaks apart at constrictions occurring between the segments of the seeds. Genera The tribe consists of the following ge ...

DC.,

Trifolieae The tribe Trifolieae is one of the subdivisions of the plant family Fabaceae. It is included within the inverted repeat-lacking clade (IRLC). All of the members of this tribe are trifoliate. These genera are recognized by the USDA: * '' Medicago ...

Endl.) and several genera that were traditionally placed in the tribe

Millettieae The tribe Millettieae is one of the subdivisions of the plant family Fabaceae. The following genera are recognized by the USDA. In 2019, some genera USDA places in this tribe were moved to tribe Wisterieae; these are listed at the end. * ''A ...

: '' Afgekia'', ''

Callerya ''Callerya'' is a genus of flowering plants in the legume family, Fabaceae. It belongs to the subfamily Faboideae. Genetic analysis shows ''Callerya'' and ''Wisteria'' to be each other's closest relatives and quite distinct from other members of ...

'', ''

Endosamara ''Endosamara'' is a monotypic genus of flowering plants in the legume family Fabaceae, tribe Wisterieae. Its only species is ''Endosamara racemosa'', a liana found from South India through Indo-China to the Philippines. Description ''Endosa ...

'', ''

Sarcodum ''Sarcodum'' is a genus of flowering plants in the legume family, Fabaceae. It belongs to the subfamily Faboideae, tribe Wisterieae. Its three species are twining vines growing over shrubs, and are native from southeast mainland China to the So ...

'', ''

Wisteria ''Wisteria'' is a genus of flowering plants in the legume family, Fabaceae (Leguminosae), that includes ten species of woody twining vines that are native to China, Japan, Korea, Vietnam, Southern Canada, the Eastern United States, and north o ...

'', and possibly '' Antheroporum''. The first five of these genera have been transferred to the tribe

Wisterieae Wisterieae is a tribe of flowering plants in the bean family Fabaceae. The tribe was first described in 1994 for the sole genus ''Wisteria'', but was greatly expanded in 2019 to include 13 genera, six of which were new. Five had previously been ...

, so that as revised, the tribe Millettieae falls outside the IRLC clade. The clade is defined as:

"The most inclusive
crown clade In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
exhibiting the structural mutation in the
plastid The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosy ...
genome (loss of one copy of the ~25-kb inverted repeat region) homologous with that found in ''
Galega officinalis ''Galega officinalis'', commonly known as galega or goat's-rue, is an herbaceous plant in the subfamily Faboideae of the legume family Fabaceae. It is native to parts of northern Africa, western Asia and Europe, but is widely cultivated and natu ...
'' L. 1753, ''
Glycyrrhiza lepidota ''Glycyrrhiza lepidota'' (American licorice) is a species of ''Glycyrrhiza'' (a genus in the pea/bean family, Fabaceae) native to most of North America, from central Canada south through the United States to California, Texas and Virginia, but ...
'' Nuttall 1813, and ''
Vicia faba ''Vicia faba'', commonly known as the broad bean, fava bean, or faba bean, is a species of vetch, a flowering plant in the pea and bean family Fabaceae. It is widely cultivated as a crop for human consumption, and also as a cover crop. Variet ...
'' L., where these taxa are extant species included in the crown clade defined by this name."

References

External links

The IRLC at the Tree of Life
{{Taxonbar, from=Q16983603

Inverted repeat-lacking clade The inverted repeat-lacking clade (IRLC) is a monophyletic clade of the flowering plant subfamily Faboideae (or Papilionaceae). Faboideae includes the majority of agriculturally-cultivated legumes. The name of this clade is informal and is not ...

Plant unranked clades