plum-yew vs coniferous tree

plum-yew and coniferous tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
plum-yew	Yes	No	No	No
coniferous tree	Yes	No	No	No

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

plum-yew: any of several evergreen trees and shrubs of eastern Asia resembling yew and having large seeds enclosed in a fleshy envelope; sometimes cultivated as ornamentals
coniferous tree: any gymnospermous tree or shrub bearing cones

Other hypernyms of plum-yew include conifer.

plum-yew (noun)	coniferous tree (noun)
any of several evergreen trees and shrubs of eastern Asia resembling yew and having large seeds enclosed in a fleshy envelope; sometimes cultivated as ornamentals	any gymnospermous tree or shrub bearing cones