class Monocotyledonae vs monocotyledon

class Monocotyledonae and monocotyledon both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Monocotyledonae	Yes	No	No	No
monocotyledon	Yes	No	No	No

class Monocotyledonae (noun)	monocotyledon (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	a monocotyledonous flowering plant; the stem grows by deposits on its inside