Pinus mugo vs pine tree

Pinus mugo and pine tree both are nouns.

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

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

Pinus mugo: low shrubby pine of central Europe with short bright green needles in bunches of two
pine tree: a coniferous tree

Other hypernyms of Pinus mugo include pine, true pine.

Pinus mugo (noun)	pine tree (noun)
low shrubby pine of central Europe with short bright green needles in bunches of two	a coniferous tree