Eudicots , Eudicotidae or eudicotyledons are a clade of flowering plants primarily characterized by having two seed leaves upon germination. [1] This word is derived from dicotyledonous .
Traditionally they were called tricolpates or non -magnoliid dicots by previous authors. The botanical case was introduced in 1991 by evolutionary botanist James A. Doyle and paleobotanist Carol L. Hotton to emphasize the later evolutionary variation of tricolpate dicots from earlier, less specialized, dicots.
Many familiar plants are eudicots, including many common edible plants, trees, and ornamentals. Some common and familiar eudicots include: sunflower , dandelion , maze -not , cabbage , apple , buttercup , maple and macadamia. Most mid-latitude deciduous trees also belong to eudicots, with notable exceptions being magnolia and tulip trees related to magnoliids, and Ginkgo biloba, which is not an angiosperm.
description
The close relationship between flowering plants with triangular pollen grains was initially observed in morphological studies of shared derived characters. The pollen grains in these plants have a distinctive feature of displaying three colepi or bracts parallel to the polar axis. [3]
Later molecular evidence confirmed the genetic basis for the evolutionary relationship between flowering plants with tricolpate pollen grains and dicotyledonous traits. The term means “true dicot”, as it contains most plants that are considered dicotyledonous and have dicotyledonous characteristics. The term “eudicots” has since been widely adopted in botany to refer to one of the two largest groups of angiosperms (constituting over 70% of angiosperm species), with monocots being the other. The remaining angiosperms include the magnoliids and are sometimes called basal angiosperms or paleodicots, but these terms have not been widely or consistently adopted, as they do not refer to a monophyletic group.
classification
The old name for eudicots is Tricolpets , a name that refers to the oval structure of the pollen. Members of the group have tricolpate pollen, or forms derived from it. These pollens have three or more holes in the groove called colpi. In contrast, most other seed plants (that is, gymnosperms, monocots, and palaeodicots) produce monosulcate pollen, in which a single pore is set in a separately oriented groove called the sulcus. The name “Tricholptes” is preferred by some botanists to avoid confusion with dicots, a non-monophyletic group. [4]
The name “eudicots” (plural) is used in the APG system (from the APG system of 1998 to the APG IV system of 2016) for the classification of angiosperms. This applies to a clade, a monophyletic group, which includes most of the (former) dicots.
“Tricholpet” is a synonym for the “eudicot” monophyletic group, “true dicotyledons” (which are distinguished from all other flowering plants by their tricolpate pollen structure). The number of furrows or pores in the pollen grain helps classify flowering plants, with eudicots having three colpi ( tricolpate ), and other groups having one sulcus. [5] [4]
Pollen pore is any modification of the wall of the pollen grain. These modifications include thinning, ridges and pores, they serve as an exit for pollen material and allow the grain to shrink and swell due to changes in moisture content. Enlarged pores/ grooves in pollen grains called colpi (singular colpus ) are a main criterion for identification of pollen classes with pores. [6]
subdivisions
Eudicots can be divided into two groups: basal eudicots and core eudicots. [7] A basal eudicot is an informal name for a paraphyletic group. Core eudicots are a monophyletic group. [8] A 2010 study suggested that core eudicots may be divided into two groups, a clade called Gunnerales and Pentapetalae , which includes all remaining core eudicots . [9]
The pentapetale can then be divided into three classes:
- delineals
- Consisting of the superrosids Saxifragales and Rozid (the APG IV system Rosid also includes Vitales)
- Consisting of the superasterids Santalales, Berberidopsidales, Caryophyllales and Asterids
This division of eudicots is shown in the following cladogram:
The following is a more detailed analysis according to APG IV, displayed within each clade and order:
The following is a more detailed analysis according to APG IV, displayed within each clade and order: [11]
clade eudicots
Order Ranuncules
order proteless
Order Trochodendrales
order boxless
clade core eudicots
command gunless
order delinquents
clade superosids
Order Saxifragales
clade rosids
order vitals
clade fabids
Order Fabales
order rossels
Order Fagales
Order Cucurbitales
Order Oxleydales
order malpighiales
Order Celestrales
order zygophiles
clade malvids
order geranialus
Order Myrtales
Order Crosssomatales
Order Picramniales
Order received
Order Brassicales
Order of gardeners
Order Sapindales
clade superasterids
order barberidopsidales
order santaless
Order Caryophyllales
clade asteroids
order cornless
order ericles
clade campanulids
order aquifolials
order esterless
order escaloniales
order bruniels
order appiales
order dipscals
Order Paracryphiales
clade lamids
Order Solanelles
order lamiales
order vahliales
Order Gentianales
order boraginales
order garageless
order metaneous
Order Icacinales
