conifer vs coniferous

conifer is a noun but coniferous is not a noun.

Word	Noun	Adjective	Verb	Adverb
conifer	Yes	No	No	No
coniferous	No	Yes	No	No

conifer (noun)	coniferous (noun)
any gymnospermous tree or shrub bearing cones

conifer (adjective)	coniferous (adjective)
	of or relating to or part of trees or shrubs bearing cones and evergreen leaves