Liliidae is a botanical name at the rank of subclass. Circumscription of the subclass will vary with the taxonomic system being used (there are many such systems); the only requirement being that it includes the family Liliaceae.

Liliidae in Takhtajan system

The Takhtajan system treats this as one of six subclasses within class Liliopsida (= monocotyledons). This subclass consists of:

Liliidae in Cronquist system

The Cronquist system treats this as one of five subclasses within class Liliopsida (= monocotyledons), and it consists of:

Liliidae in Dahlgren and Thorne systems

In the Dahlgren system and the Thorne system (1992) this is an important name: this subclass comprises the monocotyledons (in APG II these are the monocots).

Dahlgren (1985)

Thorne (1992)

(in the version of the system as depicted by Reveal)

Liliidae in APG II system

The APG and APG II systems do not use formal botanical names above the rank of order, and names such as Liliopsida and Liliidae have no place in these systems.