class Psilopsida vs order Psilotales

class Psilopsida and order Psilotales both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Psilopsida	Yes	No	No	No
order Psilotales	Yes	No	No	No

class Psilopsida (noun)	order Psilotales (noun)
whisk ferns; comprising the family Psilotaceae or Psilotatae: vascular plants with no roots, partial if any leaf differentiation, and rudimentary spore sacs	lower vascular plants having dichotomously branched sporophyte divided into aerial shoot and rhizome and lacking true roots