class Dicotyledonae vs order Casuarinales

class Dicotyledonae and order Casuarinales both are nouns.

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

class Dicotyledonae (noun)	order Casuarinales (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	order of chiefly Australian trees and shrubs comprising the casuarinas; 1 family: Casuarinaceae