class Dicotyledones vs dicot genus

class Dicotyledones and dicot genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Dicotyledones	Yes	No	No	No
dicot genus	Yes	No	No	No

class Dicotyledones (noun)	dicot genus (noun)
comprising seed plants that produce an embryo with paired cotyledons and net-veined leaves; divided into six (not always well distinguished) subclasses (or superorders): Magnoliidae and Hamamelidae (considered primitive), Caryophyllidae (an early and distinctive offshoot), and three more or less advanced groups: Dilleniidae, Rosidae, Asteridae	genus of flowering plants having two cotyledons (embryonic leaves) in the seed which usually appear at germination