Classification System: APG II
* Angiosperm Phylogeny Group; 2003; "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering: APG II" Botanical Journal of the Linnean Society 141:399–436 
Eudicots and Eudicotyledons are terms introduced by Doyle & Hotton (1991) to refer to a monophyletic group of flowering plants that had been called tricolpates or non-Magnoliid dicots by previous authors. The term means, literally, "true dicotyledons" as it contains the majority of plants that have been considered dicotyledons and have typical dicotyledonous characters. The term "eudicots" has been widely adopted to refer to one of the two largest clades of angiosperms (constituting >70% of all angiosperms), monocots being the other. The remaining dicots are sometimes referred to as paleodicots but this term has not been widely adopted as it does not refer to a monophyletic group.
A large number of familiar plants are eudicots. A few are forget-me-not, cabbage, apple, dandelion, buttercup, maple and macadamia.
Another name for the eudicots is tricolpates, a name which refers to the structure of the pollen. The group has tricolpate pollen, or forms derived from it. These pollen have three or more pores set in furrows called colpi. In contrast, most of the other seed plants (that is the gymnosperms, 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 in order to avoid confusion with the dicots, a non-monophyletic group (Judd & Olmstead 2004).
The name eudicots (plural) is used in the APG system, of 1998, and APG II system, of 2003, for classification of angiosperms. It is applied to a clade, a monophyletic group, which includes most of the (former) dicotyledons.
The eudicots can be divided into two groups: the basal eudicots and the core eudicots.  Basal eudicots is an informal name for a paraphyletic group. The core eudicots are a monophyletic group. 
A second study has suggested that the eudicots can be divided into two clades - Pentapetalae - comprising all core eudicots except Gunnerales - and Gunnerales.
Pentapetalae can be then divided into three clades:
* (i) a "superrosid" clade consisting of Rosidae, Vitaceae and Saxifragales
Within the core eudicots, the largest groups are the "rosids" (core group with the prefix "eu−") and the "asterids" (core group with the prefix "eu−").
* eudicots :
core eudicots :
In more detail, within each clade some unplaced families and orders (unplaced genera are not mentioned):
* clade eudicots
family Buxaceae [+ family Didymelaceae]
clade core eudicots
clade eurosids I
family Zygophyllaceae [+ family Krameriaceae]
clade eurosids II
clade euasterids I
clade euasterids II
Note : “ + ....” = optional, as a segregate of the previous family.
1. ^ Worberg A, Quandt D, Barniske A-M, Löhne C, Hilu KW, Borsch T (2007) Phylogeny of basal eudicots: insights from non-coding and rapidly evolving DNA. Organisms, Diversity and Evolution 7 (1), 55-77.
* Doyle, J. A. & Hotton, C. L. Diversification of early angiosperm pollen in a cladistic context. Pp. 169-195 in Pollen and Spores. Patterns of Diversification (eds Blackmore, S. & Barnes, S. H.) (Clarendon, Oxford, 1991).
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