class Dicotyledonae vs order Primulales

class Dicotyledonae and order Primulales both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Dicotyledonae	Yes	No	No	No
order Primulales	Yes	No	No	No

class Dicotyledonae (noun)	order Primulales (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	Primulaceae, Theophrastaceae, Myrsinaceae, and (in some classifications) Plumbaginaceae