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Magnoliopsida is the botanical name for a class of flowering plants. By definition the class will include the family Magnoliaceae, but its circumscription can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed.

Contents 1 Cronquist and Takhtajan systems 1.1 Magnoliopsida in the Takhtajan system 1.2 Magnoliopsida in the Cronquist system 2 Dahlgren and Thorne systems 3 Reveal system 4 APG systems

In the Takhtajan system and the Cronquist system the name is used for the group known as dicotyledons.

The Takhtajan system used this internal taxonomy:

• class Magnoliopsida [= dicotyledons]

  subclass Magnoliidae

  subclass Nymphaeidae

  subclass Nelumbonidae

  subclass Ranunculidae

  subclass Caryophyllidae

  subclass Hamamelididae

  subclass Dilleniidae

  subclass Rosidae

  subclass Cornidae

  subclass Asteridae

  subclass Lamiidae

The Cronquist system used this internal taxonomy (in the 1981 version):

• class Magnoliopsida [= dicotyledons]

  subclass Magnoliidae

  subclass Hamamelidae

  subclass Caryophyllidae

  subclass Dilleniidae

  subclass Rosidae

  subclass Asteridae

The Dahlgren system and the Thorne system (1992) use the name Magnoliopsida for the flowering plants (angiosperms). However, the Cronquist system has been very popular and there have been many versions of the system published. In some of these Cronquist-based systems the name Magnoliopsida (at the rank of class) refers to the flowering plants (the angiosperms).

• class Magnoliopsida [= angiosperms]

  subclass Magnoliidae [= dicotyledons]

  subclass Liliidae [= monocotyledons]

The Reveal system uses the name Magnoliopsida for a group of the primitive dicotyledons, corresponding to about half of the plants in the magnoliids:

• class 1. Magnoliopsida

  superorder 1. Magnolianae

  superorder 2. Lauranae

In the APG and APG II systems botanical names are used only at the rank of order and below. Above the rank of order, these systems use their own names, such as angiosperms, eudicots, monocots, rosids, etc. These names refer to clades (unranked). This class Magnoliopsida is not defined. Note that the idea that dicotyledons could be a taxonomic unit and get a formal name is rejected by the APG: the dicots are paraphyletic.