Word Study
liliopsida
CIDE DICTIONARY
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; Commelinidae; and Liliidae. [WordNet 1.5]
For further exploring for "liliopsida" in Webster Dictionary Online