continual vs perennial

continual is not a noun while perennial is a noun.

Word	Noun	Adjective	Verb	Adverb
continual	No	Yes	No	No
perennial	Yes	Yes	No	No

continual (noun)	perennial (noun)
	(botany) a plant lasting for three seasons or more

continual (adjective)	perennial (adjective)
recurring regularly or frequently in a prolonged and closely spaced series	lasting three seasons or more
having no interruptions	recurring again and again
	lasting an indefinitely long time; suggesting self-renewal