Pinus densiflora vs pine tree

Pinus densiflora and pine tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pinus densiflora	Yes	No	No	No
pine tree	Yes	No	No	No

As nouns, pine tree is a hypernym of Pinus densiflora; that is, pine tree is a word with a broader meaning than Pinus densiflora:

Pinus densiflora: pine native to Japan and Korea having a wide-spreading irregular crown when mature; grown as an ornamental
pine tree: a coniferous tree

Other hypernyms of Pinus densiflora include pine, true pine.

Pinus densiflora (noun)	pine tree (noun)
pine native to Japan and Korea having a wide-spreading irregular crown when mature; grown as an ornamental	a coniferous tree