Magnoliopsida is a valid botanical name for a class of . By definition the class will include the family Magnoliaceae, but its can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed.
Classification
Cronquist and Takhtajan systems
In the
Takhtajan system and the
Cronquist system, the name was used for the group known as
dicotyledons.
The Takhtajan system used this internal taxonomy:
-
class Magnoliopsida (= dicotyledons)
The Cronquist system used this internal taxonomy (in the 1981 version):
-
class Magnoliopsida (= dicotyledons)
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 (angiosperms).
Dahlgren and Thorne systems
The
Dahlgren system and the
Thorne system (1992) used the name Magnoliopsida for the flowering plants.
-
class Magnoliopsida (= angiosperms)
Reveal system
The
Reveal system used the name Magnoliopsida for a group of the primitive dicotyledons, corresponding to about half of the plants in the
magnoliids:
APG systems
In the
APG system 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
(unranked). The class Magnoliopsida is not defined. The idea that dicotyledons are a taxonomic unit and require a formal name is rejected by the APG: the dicots are considered to be
paraphyletic.