rosid dicot genus vs subclass Rosidae

rosid dicot genus and subclass Rosidae both are nouns.

Word	Noun	Adjective	Verb	Adverb
rosid dicot genus	Yes	No	No	No
subclass Rosidae	Yes	No	No	No

rosid dicot genus (noun)	subclass Rosidae (noun)
a genus of dicotyledonous plants	a group of trees and shrubs and herbs mostly with polypetalous flowers; contains 108 families including Rosaceae, Crassulaceae, Myrtaceae, Melastomaceae, Euphorbiaceae, Umbelliferae