Divided into four subclasses or superorders Alismatidae

• Comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves includes grasses and lilies and palms and orchids
• And Liliidae
• Arecidae
• Commelinidae

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Monocotyledonae \Monocotyledonae\, Monocotyledones \Monocotyledones\prop. n. A class of plants comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves: grasses; lilies; palms; and orchids. It is divided into four ...