Pinus virginiana vs pine tree

Pinus virginiana and pine tree both are nouns.

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

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

Pinus virginiana: common small shrubby pine of the eastern United States having straggling often twisted or branches and short needles in bunches of 2
pine tree: a coniferous tree

Other hypernyms of Pinus virginiana include pine, true pine.

Pinus virginiana (noun)	pine tree (noun)
common small shrubby pine of the eastern United States having straggling often twisted or branches and short needles in bunches of 2	a coniferous tree