Magnoliidae is a botanical name of a subclass. The of the subclass will vary with the being used (there are many such systems). The only requirement is that it must include the family Magnoliaceae (Art 16 of the ICBN). Cronquist system The Cronquist system used this name for one of six subclasses (within class Magnoliopsida = dicotyledons). In the original version of this system the circumscription was (1981): subclass Magnoliidae : : order Magnoliales : order Laurales : order Piperales : o… (More on Magnoliidae)