The eudicots, Eudicotidae, or eudicotyledons are a
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 ter ...
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 t ...
s mainly characterized by having two
seed leaves
A cotyledon (; ; ; , gen. (), ) is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The nu ...
upon germination. The term derives from
Dicotyledon
The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, t ...
s.
Traditionally they were called tricolpates or non-
magnoliid
Magnoliids (or Magnoliidae or Magnolianae) are a clade of flowering plants. With more than 10,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others, it is the third-largest group of a ...
dicots by previous authors. The botanical terms were introduced in 1991 by evolutionary botanist
James A. Doyle
James is a common English language surname and given name:
*James (name), the typically masculine first name James
* James (surname), various people with the last name James
James or James City may also refer to:
People
* King James (disambiguat ...
and paleobotanist Carol L. Hotton to emphasize the later evolutionary divergence of tricolpate
dicots from earlier, less specialized, dicots.
Numerous familiar plants are eudicots, including many common food plants, trees, and ornamentals. Some common and familiar eudicots include
sunflower
The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), ...
,
dandelion
''Taraxacum'' () is a large genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus is native to Eurasia and Nor ...
,
forget-me-not,
cabbage
Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.&n ...
,
apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...
,
buttercup
''Ranunculus'' is a large genus of about almost 1700 to more than 1800 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots.
The genus is distributed in Europe, ...
,
maple
''Acer'' () is a genus of trees and shrubs commonly known as maples. The genus is placed in the family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated since h ...
, and
macadamia. Most leafy trees of midlatitudes also belong to eudicots, with notable exceptions being magnolias and tulip trees which belong to
magnoliids
Magnoliids (or Magnoliidae or Magnolianae) are a clade of flowering plants. With more than 10,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others, it is the third-largest group of a ...
, and ''
Ginkgo biloba
''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of tree native to China. It is the last living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossils ...
'', which is not an
angiosperm
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 ...
.
Description
The close relationships among flowering plants with
tricolpate pollen grains was initially seen in morphological studies of
shared derived characters. These plants have a distinct trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis.
Later
molecular
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bio ...
evidence confirmed the genetic basis for the evolutionary relationships among flowering plants with tricolpate pollen grains and dicotyledonous traits. The term means "true dicotyledons", as it contains the majority of plants that have been considered dicots and have
characteristics of the dicots. One of the genetic traits which defines the eudicots is the
duplication
Duplication, duplicate, and duplicator may refer to:
Biology and genetics
* Gene duplication, a process which can result in free mutation
* Chromosomal duplication, which can cause Bloom and Rett syndrome
* Polyploidy, a phenomenon also known ...
of
DELLA protein‐encoding genes in their
most recent common ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
. The term "eudicots" has subsequently been widely adopted in
botany
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
to refer to one of the two largest clades of
angiosperm
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 ...
s (constituting over 70% of the angiosperm species),
monocots
Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...
being the other. The remaining angiosperms include
magnoliids
Magnoliids (or Magnoliidae or Magnolianae) are a clade of flowering plants. With more than 10,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others, it is the third-largest group of a ...
and what are sometimes referred to as
basal angiosperms
The basal angiosperms are the flowering plants which diverged from the lineage leading to most flowering plants. In particular, the most basal angiosperms were called the ANITA grade, which is made up of ''Amborella'' (a single species of shrub f ...
or paleodicots, but these terms have not been widely or consistently adopted, as they do not refer to 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 gr ...
group.
Taxonomy
The earlier name for the eudicots is tricolpates, a name which refers to the grooved structure of the
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...
. Members of the group have tricolpate pollen, or forms derived from it. These pollens have three or more pores set in furrows called colpi. In contrast, most of the other
seed plants (that is the
gymnosperms
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν� ...
, the monocots and the paleodicots) produce monosulcate pollen, with a single pore set in a differently oriented groove called the sulcus. The name "tricolpates" is preferred by some botanists to avoid confusion with the dicots, a nonmonophyletic group.
The name "eudicots" (plural) is used in the
APG systems (from
APG system
The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved A ...
, of 1998, to
APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published ...
, of 2016) for classification of angiosperms. It is applied to a
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 ter ...
, a monophyletic group, which includes most of the (former) dicots.
"Tricolpate" is a synonym for the "
Eudicot
The eudicots, Eudicotidae, or eudicotyledons are a clade of flowering plants mainly characterized by having two seed leaves upon germination. The term derives from Dicotyledons.
Traditionally they were called tricolpates or non-magnoliid dico ...
"
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 gr ...
group, the "true
dicotyledons
The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, ...
" (which are distinguished from all other flowering plants by their tricolpate
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...
structure). The number of
pollen grain ''furrows'' or ''pores'' helps classify 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 t ...
s, with eudicots having three
colpi (tricolpate), and other groups having one
sulcus.
[
Pollen ]aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
An ...
s are any modification of the wall of the pollen grain. These modifications include thinning, ridges and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. The elongated apertures/ furrows in the pollen grain are called ''colpi'' (singular ''colpus''), which, along with pores, are a chief criterion for identifying the pollen classes.
Subdivisions
The eudicots can be divided into two groups: the basal eudicots and the core eudicots. Basal eudicot is an informal name for a paraphyletic
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...
group. The core eudicots are a monophyletic group.[
] A 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae, comprising all the remaining core eudicots.[
The Pentapetalae can be then divided into three clades:
* Dilleniales
* superrosids consisting of Saxifragales and ]rosids
The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms.
The clade is divided into 16 to 20 orders, depending upon circumscription and classificati ...
(the APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published ...
includes the Vitales in the rosids)
* superasterids consisting of Santalales, Berberidopsidales, Caryophyllales
Caryophyllales ( ) is a diverse and heterogeneous order of flowering plants that includes the cacti, carnations, amaranths, ice plants, beets, and many carnivorous plants. Many members are succulent, having fleshy stems or leaves. The betalai ...
and asterids
In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade (a monophyletic group). Asterids is the largest group of flowering plants, with more than 80,000 species, about a third of the total fl ...
This division of the eudicots is shown in the following cladogram:[Based on:]
----
The following is a more detailed breakdown according to APG IV
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...
, showing within each clade and orders:
* clade Eudicots
*: order Ranunculales
Ranunculales is an order of flowering plants. Of necessity it contains the family Ranunculaceae, the buttercup family, because the name of the order is based on the name of a genus in that family. Ranunculales belongs to a paraphyletic group kno ...
*: order Proteales
Proteales is an order of flowering plants consisting of three (or four) families. The Proteales have been recognized by almost all taxonomists.
The representatives of the Proteales are very different from each other. The order contains plants ...
*: order Trochodendrales
Trochodendraceae is the only family of flowering plants in the order Trochodendrales. It comprises two extant genera, each with a single species along with up to five additional extinct genera and a number of extinct species. The living spe ...
*: order Buxales
The Buxales are a small order of eudicot flowering plants, recognized by the APG IV system of 2016. The order includes the family Buxaceae; the families Didymelaceae and Haptanthaceae may also be recognized or may be included in the Buxaceae. Ma ...
*: clade Core eudicots
*:: order Gunnerales
*:: order Dilleniales
*:: clade Superrosids
*::: order Saxifragales
*::: clade Rosids
The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms.
The clade is divided into 16 to 20 orders, depending upon circumscription and classificati ...
*:::: order Vitales
The Vitaceae are a family of flowering plants, with 14 genera and around 910 known species, including common plants such as grapevines (''Vitis'' spp.) and Virginia creeper (''Parthenocissus quinquefolia''). The family name is derived from the g ...
*:::: clade Fabids
*::::: order Fabales
The Fabales are an order of flowering plants included in the rosid group of the eudicots in the Angiosperm Phylogeny Group II classification system. In the APG II circumscription, this order includes the families Fabaceae or legumes (including ...
*::::: order Rosales
*::::: order Fagales
The Fagales are an order of flowering plants, including some of the best-known trees. The order name is derived from genus ''Fagus'', beeches. They belong among the rosid group of dicotyledons. The families and genera currently included are as ...
*::::: order Cucurbitales
*::::: order Oxalidales
*::::: order Malpighiales
The Malpighiales comprise one of the largest orders of flowering plants, containing about 36 families and more than species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsett ...
*::::: order Celastrales
*::::: order Zygophyllales
*:::: clade Malvids
*::::: order Geraniales
*::::: order Myrtales
The Myrtales are an order of flowering plants placed as a sister to the eurosids II clade as of the publishing of the ''Eucalyptus grandis'' genome in June 2014.
The APG III system of classification for angiosperms still places it within the e ...
*::::: order Crossosomatales
The Crossosomatales are an order, first recognized as such by APG II. They are flowering plants included within the Rosid eudicots.
Description
Species assigned to the Crossosomatales have in common flowers that are positioned solitarily, wit ...
*::::: order Picramniales
*::::: order Malvales
The Malvales are an order of flowering plants. As circumscribed by APG II-system, the order includes about 6000 species within 9 families. The order is placed in the eurosids II, which are part of the eudicots.
The plants are mostly shrubs and ...
*::::: order Brassicales
The Brassicales (or Cruciales) are an order of flowering plants, belonging to the eurosids II group of dicotyledons under the APG II system. One character common to many members of the order is the production of glucosinolate (mustard oil) compo ...
*::::: order Huerteales
*::::: order Sapindales
*:: clade Superasterids
The superasterids are members of a large clade ( monophyletic group) of flowering plants, containing more than 122,000 species.
The clade is divided into 20 orders as defined in APG IV system. These orders, in turn, together comprise about 14 ...
*::: order Berberidopsidales
*::: order Santalales
*::: order Caryophyllales
Caryophyllales ( ) is a diverse and heterogeneous order of flowering plants that includes the cacti, carnations, amaranths, ice plants, beets, and many carnivorous plants. Many members are succulent, having fleshy stems or leaves. The betalai ...
*::: clade Asterids
In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade (a monophyletic group). Asterids is the largest group of flowering plants, with more than 80,000 species, about a third of the total fl ...
*:::: order Cornales
*:::: order Ericales
*:::: clade Campanulids
*::::: order Aquifoliales
*::::: order Asterales
Asterales () is an order of dicotyledonous flowering plants that includes the large family Asteraceae (or Compositae) known for composite flowers made of florets, and ten families related to the Asteraceae. While asterids in general are charact ...
*::::: order Escalloniales
*::::: order Bruniales
*::::: order Apiales
*::::: order Dipsacales
The Dipsacales are an order of flowering plants, included within the asterid group of dicotyledons. In the APG III system of 2009, the order includes only two families, Adoxaceae and a broadly defined Caprifoliaceae. Some well-known members of th ...
*::::: order Paracryphiales
The Paracryphiaceae are a family of woody shrubs and trees native to Australia, southeast Asia, and New Caledonia. In the APG III system of 2009, the family is placed in its own order, Paracryphiales, in the campanulid clade of the asterids. In ...
*:::: clade Lamiids
*::::: order Solanales
The Solanales are an order of flowering plants, included in the asterid group of dicotyledons. Some older sources used the name Polemoniales for this order.
Taxonomy
Under the older Cronquist system, the latter three families were placed elsewh ...
*::::: order Lamiales
The order Lamiales (also known as the mint order) are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided into about 25 families. These families include Acanthaceae, Big ...
*::::: order Vahliales
*::::: order Gentianales
*::::: order Boraginales
*::::: order Garryales
*::::: order Metteniusales
Metteniusaceae are a family of flowering plants, the only family in the order Metteniusales. It consists of about 10 genera and 50 species of trees, shrubs, and lianas, primarily of the tropics. The family was formerly restricted to just ''Metten ...
*::::: order Icacinales
References
Bibliography
*
*
Eudicots
in Stevens, P. F. (2001 onwards)
Angiosperm Phylogeny Website
Version 7, May 2006.
External links
*
*
Eudicots
', Tree of Life Web Project
Dicots
Plant Life Forms
{{Taxonbar, from=Q165468
Plant unranked clades
Early Cretaceous plants
Extant Early Cretaceous first appearances