Commelinidae

• Comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves includes grasses and lilies and palms and orchids
• Arecidae
• Divided into four subclasses or superorders Alismatidae
• And Liliidae

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Liliopsida \Liliopsida\ n. A class comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves. It includes the grasses; lilies; palms; and orchids. It is divided into four subclasses or superorders: Alismatidae; Arecidae; ...

Wikipedia Word definitions in Wikipedia
Liliopsida Batsch ( synonym : Liliatae ) is a botanical name for the class containing the family Liliaceae (or Lily Family). It is considered synonymous (or nearly synonymous) with the name monocotyledon . Publication of the name is credited to Scopoli ...