conifer vs coniferous tree

conifer and coniferous tree both are nouns.

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

As nouns, conifer and coniferous tree are synonyms defined as:

conifer and coniferous tree: any gymnospermous tree or shrub bearing cones

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