class Monocotyledonae vs subclass Alismatidae

class Monocotyledonae and subclass Alismatidae both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Monocotyledonae	Yes	No	No	No
subclass Alismatidae	Yes	No	No	No

class Monocotyledonae (noun)	subclass Alismatidae (noun)
comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves: includes grasses and lilies and palms and orchids; divided into four subclasses or superorders: Alismatidae, Arecidae, Commelinidae, and Liliidae	one of four subclasses or superorders of Monocotyledones; comprises about 500 species in 14 families of aquatic and semiaquatic herbs