The eudicots or eudicotyledons are

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s that have two seed leaves (cotyledons) upon

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

. 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, ...

'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors have used the terms tricolpates or non-magnoliid dicots. The current botanical terms were introduced in 1991, by evolutionary botanist James A. Doyle and

paleobotanist Paleobotany or palaeobotany, also known as paleophytology, is the branch of botany dealing with the recovery and identification of plant fossils from geological contexts, and their use for the biological reconstruction of past environments (pale ...

Carol L. Hotton, to emphasize the later evolutionary

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...

of tricolpate dicots from earlier, less specialized, dicots. Scores of familiar plants are eudicots, including many commonly cultivated and edible plants, numerous

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s, tropicals and ornamentals. Among the most well-known eudicot genera are those of the

sunflower The common sunflower (''Helianthus annuus'') is a species of large annual forb of the daisy family Asteraceae. The common sunflower is harvested for its edible oily seeds, which are often eaten as a snack food. They are also used in the pr ...

(''

Helianthus ''Helianthus'' () is a genus comprising around 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of ''Helianthus'' are native to ...

''),

dandelion ''Taraxacum'' () is a 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 has a near-cosmopolitan distribu ...

(''

Taraxacum ''Taraxacum'' () is a 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 has a near-cosmopolitan distribu ...

''),

forget-me-not ''Myosotis'' ( ) is a genus of flowering plants in the family Boraginaceae. The name comes from the Ancient Greek "mouse's ear", which the foliage is thought to resemble. In the Northern Hemisphere, they are colloquially known as forget-me-no ...

('' Myosotis''),

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.& ...

(''

Brassica ''Brassica'' () is a genus of plants in the cabbage and mustard family (Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, mustard plants, or simply brassicas. Crops from this genus are sometim ...

''),

apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

(''

Malus ''Malus'' ( or ) is a genus of about 32–57 species of small deciduous trees or shrubs in the family Rosaceae, including the domesticated orchard apple, crab apples (sometimes known in North America as crabapples) and wild apples. The genus i ...

''),

buttercup ''Ranunculus'' is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed worldwide, primarily in temperate an ...

(''

Ranunculus ''Ranunculus'' is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed worldwide, primarily in temperate an ...

''),

maple ''Acer'' is a genus of trees and shrubs commonly known as maples. The genus is placed in the soapberry family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated si ...

('' Acer'') and

macadamia ''Macadamia'' is a genus of four species of trees in the flowering plant family Proteaceae. They are indigenous to Australia—specifically, northeastern New South Wales and central and southeastern Queensland. Two species of the genus are comm ...

(''Macadamia''). Most leafy, mid-latitude trees are also classified as eudicots, with notable exceptions being the

magnolia ''Magnolia'' is a large genus of about 210 to 340The number of species in the genus ''Magnolia'' depends on the taxonomic view that one takes up. Recent molecular and morphological research shows that former genera ''Talauma'', ''Dugandiodendr ...

s and American tulip tree (''

Liriodendron ''Liriodendron'' () is a genus of two species of characteristically large trees, deciduous tree, deciduous over most of their populations, in the magnolia family (biology), family (Magnoliaceae). These trees are widely known by the common name ...

'')—which belong to the

magnoliids Magnoliids, 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 angiospe ...

—and ''

Ginkgo biloba ''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of gymnosperm tree native to East Asia. It is the last living species in the order Ginkgoales, which first appeared over 290 million year ...

'', which is not an angiosperm.

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 that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

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 A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assu ...

. The term "eudicots" has subsequently been widely adopted in

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

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 (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit ...

s (constituting over 70% of the angiosperm species),

monocots Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks a ...

being the other. The remaining angiosperms include

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 biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group. According to

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

calculations, the lineage that led to eudicots split from other plants about 134

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

or 155–160 million years ago. Fossil records suggested that basal eudicots were already diverse around 121 million years ago .

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 most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

. 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 A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. la ...

(that is the

gymnosperms The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...

, 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 ...

, 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 publish ...

, of 2016) for classification of angiosperms. It is applied to a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

, a monophyletic group, which includes most of the (former) dicots. "Tricolpate" is a synonym for the "

Eudicot The eudicots or eudicotyledons are flowering plants that have two seed leaves (cotyledons) upon germination. The term derives from ''dicotyledon'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors h ...

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

structure). The number of

pollen grain Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains h ...

''furrows'' or ''pores'' helps classify the

s, with eudicots having three colpi (tricolpate), and other groups having one sulcus. Pollen

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

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 Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

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 Saxifragales is an order (biology), order of flowering plants in the Superrosids, superrosid clade of the eudicots. It contains 15 Families (biology), families and around 100 genera, with nearly 2,500 species. Well-known and economically import ...

and

rosids The rosids are members of a large clade (monophyly, 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 Order (biology), orders, depending upon Circu ...

(the

includes the Vitales in the rosids) * superasterids consisting of

Santalales The Santalales are an order (biology), order of flowering plants in the dicotyledons. Well-known members of the Santalales include Santalum, sandalwoods and the many species of mistletoes. The order has a cosmopolitan distribution, but is heavily ...

Berberidopsidales Berberidopsidales is an order of Southern Hemisphere woody flowering plants. The name is newly accepted in the APG III system of plant taxonomy. APG II system, of 2003, mentions the possibility of recognizing the order, as comprising the familie ...

Caryophyllales Caryophyllales ( ) is a diverse and heterogeneous order of flowering plants with well-known members including cacti, carnations, beets, quinoa, spinach, amaranths, pigfaces and ice plants, oraches and saltbushes, goosefoots, sundews, Venu ...

and

asterids Asterids are a large clade (monophyly, monophyletic group) of flowering plants, composed of 17 Order_(biology), orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked cl ...

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 published ...

, 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 k ...

*: 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 can be very different from each other due to their very early d ...

*: order Trochodendrales *: order Buxales *: clade Core eudicots *:: order Gunnerales *:: order Dilleniales *:: clade Superrosids *::: order

*::: clade

Rosids The rosids are members of a large clade (monophyly, 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 Order (biology), orders, depending upon Circu ...

*:::: order Vitales *:::: clade Fabids *::::: order

Fabales Fabales is 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 the s ...

*::::: order

Rosales Rosales (, ) are an order of flowering plants. Peter F. Stevens (2001 onwards). "Rosales". At: Trees At: Angiosperm Phylogeny Website. At: Missouri Botanical Garden Website. (see ''External links'' below) Well-known members of Rosales include: ...

*::::: order

Fagales The Fagales are an order of flowering plants in the rosid group of dicotyledons, including some of the best-known trees. Well-known members of Fagales include: beeches, chestnuts, oaks, walnut, pecan, hickory, birches, alders, hazels, hornb ...

*::::: order

Cucurbitales The Cucurbitales are an order of flowering plants, included in the rosid group of dicotyledons. This order mostly belongs to tropical areas, with limited presence in subtropical and temperate regions. The order includes shrubs and trees, togeth ...

*::::: order Oxalidales *::::: order

Malpighiales The Malpighiales comprise one of the largest Order (biology), orders of flowering plants. The order is very diverse, with well-known members including willows, Viola (plant), violets, aspens and Populus, poplars, Euphorbia pulcherrima, poinsett ...

*::::: order Celastrales *::::: order

Zygophyllales The Zygophyllales are an order of dicotyledonous plants, comprising the following two families: * Family Zygophyllaceae * Family Krameriaceae According to the Angiosperm Phylogeny Group (APG II) both families are unplaced to order, but neverthe ...

*:::: clade Malvids *::::: order

Geraniales Geraniales is a small order (biology), order of flowering plants, included within the rosid subclade of eudicots. The largest family (biology), family in the order is Geraniaceae with over 800 species. In addition, the order includes the smaller ...

*::::: order Myrtales *::::: 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, wi ...

*::::: order

Picramniales Picramniaceae is a small, mainly neotropical family of four genera '' Aenigmanu'', '' Alvaradoa'', '' Nothotalisia'' and '' Picramnia''. The family is the only member of the order Picramniales. Members of the family were formerly placed in the fa ...

*::::: order

Malvales The Malvales are an Order (biology), order of flowering plants. As circumscribed by Angiosperm Phylogeny Group, APG II-system, the order includes about 6000 species within nine Family (biology), families. The order is placed in the eurosids II, w ...

*::::: order

Brassicales The Brassicales (or Cruciales) are an order (biology), order of flowering plants, belonging to the malvid group of eudicotyledons under the APG IV system. Well-known members of Brassicales include cabbage, cauliflower, Brussels sprout, broccoli, ...

*::::: order

Huerteales Huerteales is the botanical name for an order of flowering plants.Peter F. Stevens (2001 onwards). "Huerteales". In: Angiosperm Phylogeny Website. In: Missouri Botanical Garden Website. (see ''External links'' below) It is one of the 17 orders t ...

*::::: order

Sapindales Sapindales is an order of flowering plants. Well-known members of Sapindales include citrus; maples, horse-chestnuts, lychees and rambutans; mangos and cashews; frankincense and myrrh; mahogany and neem. The APG III system of 2009 includ ...

*:: clade Superasterids *::: order

*::: order

*::: clade

Asterids Asterids are a large clade (monophyly, monophyletic group) of flowering plants, composed of 17 Order_(biology), orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked cl ...

*:::: order Cornales *:::: order

Ericales The Ericales are a large and diverse order of flowering plants in the asterid group of the eudicots. Well-known and economically important members of this order include tea and ornamental camellias, persimmon, ebony, blueberry, cranberry, l ...

*:::: clade

Campanulids Asterids are a large clade (monophyly, monophyletic group) of flowering plants, composed of 17 Order_(biology), orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked cl ...

*::::: order

Aquifoliales The Aquifoliales are an order of flowering plants, including the Aquifoliaceae (holly) family, and also the Helwingiaceae (2-5 species of temperate Asian shrubs) and the Phyllonomaceae (4 species of Central American trees and shrubs). In 2001, ...

*::::: order

Asterales Asterales ( ) is an Order (biology), order of dicotyledonous flowering plants that includes the large Family (biology), family Asteraceae (or Compositae) known for composite flowers made of Floret#floret, florets, and ten families related to th ...

*::::: order

Escalloniales Escalloniaceae is a family of flowering plants consisting of about 130 species in eight genera. In the APG II system it is one of eight families in the euasterids II clade (campanulids) that are unplaced as to order. More recent research has prov ...

*::::: order

Bruniales Bruniales is an order of flowering plants. Until recently it was not recognized as an order, but a 2008 study suggested that Bruniaceae and Columelliaceae are sister clades. The latest revision of the APG system, APG III The APG III system o ...

*::::: order

Apiales The Apiales are an order of flowering plants, included in the asterid group of dicotyledons. Well-known members of Apiales include carrots, celery, coriander, parsley, parsnips, poison hemlock, ginseng, ivies, and pittosporums. Apiales consi ...

*::::: 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 ...

*::::: 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 Asterids are a large clade (monophyletic group) of flowering plants, composed of 17 orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked clades lamiids (8 orders) and ...

*::::: order

Solanales The Solanales are an order of flowering plants, included in the asterid group of the eudicots. Well-known members of Solanales include potatoes, eggplants, tomatoes, chili peppers, tobacco, petunias, nightshades, morning glory, and sweet potato. ...

*::::: order

Lamiales The Lamiales (also known as the mint order) are an order of flowering plants in the asterids clade of the Eudicots. Under the APG IV system of flowering plant classification the order consists of 24 families, and includes about 23,810 species ...

*::::: order Vahliales *::::: order

Gentianales Gentianales is an order of flowering plant, included within the asterid clade of eudicots. It comprises more than 20,000 species in about 1,200 genera in 5 families. More than 80% of the species in this order belong to the family Rubiaceae. Man ...

*::::: order

Boraginales Boraginales is an order of flowering plants in the asterid clade, with a total of about 125 genera and 2,700 species. Different taxonomic treatments either include only a single family, the Boraginaceae, or divide it into up to eleven families. ...

*::::: 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 '' Mette ...

*::::: order

Icacinales Icacinales is an order of flowering plants. The order did not exist in the 2009 APG III system, and was added in the 2016 APG IV system, including two families, Icacinaceae The Icacinaceae, also called the white pear family, are a family (b ...

References

Bibliography

* *
Eudicots
in Stevens, P. F. (2001 onwards)
Angiosperm Phylogeny Website
Version 7, May 2006.

External links

* *
Eudicots
', Tree of Life Web Project * Plant Life Forms {{Taxonbar, from=Q165468 Plant unranked clades Early Cretaceous plants Extant Early Cretaceous first appearances