genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
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 ...
s, commonly known as medick or burclover, in the
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 ...
). It contains at least 87 species and is distributed mainly around the Mediterranean basin. The best-known member of the genus is
alfalfa
Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...
(''M. sativa''), an important forage crop, and the genus name is based on the Latin name for that plant, , from el, μηδική (πόα)
Median
In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...
(grass). Most members of the genus are low, creeping herbs, resembling
clover
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 ...
, but with
bur
A bur (also spelled burr) is a seed or dry fruit or infructescence that has hooks or teeth. The main function of the bur is to spread the seeds of the bur plant, often through epizoochory. The hooks of the bur are used to catch on to for exam ...
s (hence the common name). However, alfalfa grows to a height of 1 meter, and
tree medick
''Medicago arborea'' is a flowering plant species in the pea and bean family Fabaceae. Common names include moon trefoil, shrub medick, alfalfa arborea, and tree medick. It is found throughout Europe and especially in the Mediterranean basin, pr ...
(''M. arborea'') is a
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
. Members of the genus are known to produce bioactive compounds such as
medicarpin
Medicarpin is a pterocarpan, a derivative of isoflavonoids.
Natural occurrences
Medicarpin is found in ''Medicago truncatula'' and ''Swartzia madagascariensis''. It can also be found in ''Maackia amurensis'' cell cultures.
The root nodule form ...
(a
flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
triterpenoid saponin
Saponins (Latin "sapon", soap + "-in", one of), also selectively referred to as triterpene glycosides, are bitter-tasting usually toxic plant-derived organic chemicals that have a foamy quality when agitated in water. They are widely distributed ...
).
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
numbers in ''Medicago'' range from 2''n'' = 14 to 48.
The species ''
Medicago truncatula
''Medicago truncatula'', the barrelclover, strong-spined medick, barrel medic, or barrel medick, is a small annual legume native to the Mediterranean region that is used in genomic research. It is a low-growing, clover-like plant tall with trifol ...
'' is a model legume due to its relatively small stature, small genome (450–500 Mbp), short generation time (about 3 months), and ability to reproduce both by
outcrossing
Out-crossing or out-breeding is the technique of crossing between different breeds. This is the practice of introducing distantly related genetic material into a breeding line, thereby increasing genetic diversity.
Outcrossing can be a useful ...
and
selfing
Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a reproductive mechanism employed by many flowering plants. However, species o ...
.
Comprehensive descriptions of the genus are Lesinš and Lesinš 1979 and Small and Jomphe 1989. Major collections are SARDI (Australia), USDA-GRIN (United States), ICARDA (
Syria
Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...
), and INRA (France).
Evolution
''Medicago'' diverged from ''
Glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogeni ...
'' (soybean) about 53–55 million years ago (in the early
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' ...
), from '' Lotus'' (deervetch) 49–51 million years ago (also in the Eocene), and from ''
Trigonella
''Trigonella'' is a genus from the family Fabaceae. The best known member is the herb fenugreek. Members of the genus occur naturally in the Canary Islands, southern Europe, nontropical Africa, western and central Asia, the Indian subcontinent, ...
'' 10–22 million years ago (in the
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
).
Ecological interactions with other organisms
Symbiosis with nitrogen-fixing rhizobia
Béna ''et al.'' (2005) constructed a molecular phylogeny of 23 ''
Sinorhizobium
''Ensifer'' (often referred to in literature by its synonym ''Sinorhizobium'') is a genus of nitrogen-fixing bacteria ( rhizobia), three of which ('' Ensifer meliloti'', ''Ensifer medicae'' and '' Ensifer fredii'') have been sequenced.
Etymolo ...
'' strains and tested the symbiotic ability of six strains with 35 ''Medicago'' species. Comparison of these phylogenies indicates many transitions in the compatibility of the association over evolutionary time. Furthermore, they propose that the geographical distribution of strains limits the distribution of particular ''Medicago'' species.
Agricultural uses
Other than alfalfa, several of the creeping members of the family (such as ''
Medicago lupulina
''Medicago lupulina'', commonly known as black medick, nonesuch, or hop clover, is a plant of dry grassland belonging to the legume or clover family. Plants of the genus ''Medicago'', or bur clovers, are closely related to the true clovers (''Tri ...
'' and ''
Medicago truncatula
''Medicago truncatula'', the barrelclover, strong-spined medick, barrel medic, or barrel medick, is a small annual legume native to the Mediterranean region that is used in genomic research. It is a low-growing, clover-like plant tall with trifol ...
'') have been used as forage crops.
Insect herbivores
''Medicago'' species are used as food plants by the
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e of some
Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
species including the
common swift
The common swift (''Apus apus'') is a medium-sized bird, superficially similar to the barn swallow or house martin but somewhat larger, though not stemming from those passerine species, being in the order Apodiformes. The resemblances between th ...
,
flame
A flame (from Latin ''flamma'') is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density they ...
,
latticed heath
The latticed heath (''Chiasmia clathrata'') is a moth of the family Geometridae, belonging to the subfamily Ennominae, placed in the tribe Macariini. The genus was erected by Carl Linnaeus in his 1758 10th edition of ''Systema Naturae''.
Taxon ...
,
lime-speck pug
The lime-speck pug (''Eupithecia centaureata'') is a moth of the family Geometridae. It is a common species throughout the Palearctic region (where it is found in Europe, Central Asia, Mongolia, southern Siberia, eastern China (Guangdong) and Ta ...
,
nutmeg
Nutmeg is the seed or ground spice of several species of the genus ''Myristica''. ''Myristica fragrans'' (fragrant nutmeg or true nutmeg) is a dark-leaved evergreen tree cultivated for two spices derived from its fruit: nutmeg, from its seed, an ...
,
setaceous Hebrew character
The setaceous Hebrew character (''Xestia c-nigrum'') is a moth of the family Noctuidae. The species was first described by Carl Linnaeus in his 1758 10th edition of ''Systema Naturae''. It is found in the Palearctic realm. It is a common specie ...
, and
turnip
The turnip or white turnip (''Brassica rapa'' subsp. ''rapa'') is a root vegetable commonly grown in temperate climates worldwide for its white, fleshy taproot. The word ''turnip'' is a compound of ''turn'' as in turned/rounded on a lathe and ' ...
moths and case-bearers of the genus ''
Coleophora
''Coleophora'' is a very large genus of moths of the family Coleophoridae. It contains some 1,350 described species. The genus is represented on all continents, but the majority are found in the Nearctic and Palaearctic regions. Many authors hav ...
'', including ''C. frischella'' (recorded on ''M. sativa'') and ''C. fuscociliella'' (feeds exclusively on ''Medicago'' spp.).
Medicago persica
''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 i ...
Medicago arborea
''Medicago arborea'' is a flowering plant species in the pea and bean family Fabaceae. Common names include moon trefoil, shrub medick, alfalfa arborea, and tree medick. It is found throughout Europe and especially in the Mediterranean basin, pri ...
Medicago lupulina
''Medicago lupulina'', commonly known as black medick, nonesuch, or hop clover, is a plant of dry grassland belonging to the legume or clover family. Plants of the genus ''Medicago'', or bur clovers, are closely related to the true clovers (''Tri ...
Medicago hybrida
''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 i ...
Medicago pironae
''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 ...
Medicago sativa
Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as we ...
'' L. (alfalfa)
** ''M. s. caerulea''
** ''M. s. falcata ''(''
Medicago falcata
''Medicago falcata'' is a plant species of the genus '' Medicago''. It is native to much of Europe and Asia, but is found throughout the world. It forms a symbiotic relationship with the bacterium ''Sinorhizobium meliloti'', which is capable of ...
'')
*** ''M. s. f.'' var. ''falcata''
*** ''M. s. f. ''var. ''viscosa''
** ''M. s. glomerata''
** ''M. s. sativa''
* '' Medicago saxatilis'' M. Bieb
* '' Medicago suffruticosa'' Ramond ex DC.
**''M. s. leiocarpa''
**''M. s. suffruticosa''
Section Orbiculares
* ''
Medicago orbicularis
''Medicago orbicularis'' is a plant species found throughout the Mediterranean basin and along the European Black Sea coast. It forms a symbiosis, symbiotic relationship with the bacterium ''Sinorhizobium medicae'', which is capable of nitrogen f ...
Medicago cretacea
''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 ...
Medicago ruthenica
''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 ...
Medicago rugosa
''Medicago rugosa'', the wrinkled medick, is a species of annual herb in the family Fabaceae. They have a self-supporting growth form and compound, broad leaves. Individuals can grow to 0.2 m.
Sources
References
{{Taxonbar, from=Q15434695
...
Medicago ciliaris
''Medicago ciliaris'', the ciliate medick, is a plant species of the genus ''Medicago''. It is found throughout the Mediterranean basin. It forms a symbiotic relationship with the bacterium ''Sinorhizobium medicae'', which is capable of nitrogen ...
'' (L.) Krocker
* ''
Medicago granadensis
''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 ...
'' Willd.
* ''
Medicago intertexta
''Medicago intertexta'', the hedgehog medick, Calvary clover, or Calvary medick, is a flowering plant of the family ''Fabaceae''. It is found primarily in the western Mediterranean basin. It forms a symbiotic relationship with the bacterium ''Sin ...
Medicago arabica
''Medicago arabica'', the spotted medick, spotted burclover, heart clover, is a flowering plant in the pea and bean family Fabaceae. It is native to the Mediterranean basin but is found throughout the world, usually on clifftop grasslands and gra ...
Medicago minima
''Medicago minima'' is a plant species of the genus ''Medicago''. It is native to the Mediterranean basin but is found worldwide. It forms a symbiotic relationship with the bacterium ''Sinorhizobium meliloti'', which is capable of nitrogen fixati ...
'' (L.) Bart.
* ''
Medicago polymorpha
''Medicago polymorpha'' is a plant species of the genus ''Medicago''. It is native to the Mediterranean basin but is found throughout the world. It forms a symbiotic relationship with the bacterium ''Sinorhizobium medicae'', which is capable of n ...
Medicago littoralis
''Medicago littoralis'' is a plant species of the genus '' Medicago''. It is found primarily in the Mediterranean basin. It forms a symbiotic relationship with the bacterium ''Sinorhizobium meliloti'', which is capable of nitrogen fixation
Ni ...
Medicago rigiduloides
''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 i ...
Medicago truncatula
''Medicago truncatula'', the barrelclover, strong-spined medick, barrel medic, or barrel medick, is a small annual legume native to the Mediterranean region that is used in genomic research. It is a low-growing, clover-like plant tall with trifol ...
The status of the following species is unresolved:
* ''Medicago agropyretorum'' Vassilcz.
* ''Medicago alatavica'' Vassilcz.
* ''Medicago caucasica'' Vassilcz.
* ''Medicago cyrenaea'' Maire & Weiller
* ''Medicago difalcata'' Sinskaya
* ''Medicago grossheimii'' Vassilcz.
* ''Medicago gunibica'' Vassilcz.
* ''Medicago hemicoerulea'' Sinskaya
* ''Medicago karatschaica'' (A. Heller) A. Heller
* ''Medicago komarovii'' Vassilcz.
* ''Medicago meyeri'' Gruner
* ''Medicago polychroa'' Grossh.
* ''Medicago schischkinii'' Sumnev.
* ''Medicago talyschensis'' Latsch.
* ''Medicago transoxana'' Vassilcz.
* ''Medicago tunetana'' (Murb.) A.W. Hill
* ''Medicago vardanis' Vassilcz.
* ''Medicago virescens'' Grossh.
Recent molecular phylogenic analyses of ''Medicago'' indicate that the sections and subsections defined by Small & Jomphe, as outlined above, are generally
polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...
. However, with minor revisions sections and subsections could be rendered
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 ...