spruce vs coniferous tree

spruce and coniferous tree both are nouns.

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

As nouns, coniferous tree is a hypernym of spruce; that is, coniferous tree is a word with a broader meaning than spruce:

Other hypernyms of spruce include conifer.

spruce (noun)	coniferous tree (noun)
any coniferous tree of the genus Picea	any gymnospermous tree or shrub bearing cones
light soft moderately strong wood of spruce trees; used especially for timbers and millwork

spruce (adjective)	coniferous tree (adjective)
marked by up-to-dateness in dress and manners

spruce (verb)	coniferous tree (verb)
dress and groom with particular care, as for a special occasion
make neat, smart, or trim