Japanese cedar vs cedar tree

Japanese cedar and cedar tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Japanese cedar	Yes	No	No	No
cedar tree	Yes	No	No	No

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

Japanese cedar: tall evergreen of Japan and China yielding valuable soft wood
cedar tree: any of numerous trees of the family Cupressaceae that resemble cedars

Other hypernyms of Japanese cedar include cedar.

Japanese cedar (noun)	cedar tree (noun)
tall evergreen of Japan and China yielding valuable soft wood	any cedar of the genus Cedrus
	any of numerous trees of the family Cupressaceae that resemble cedars