Scotch fir vs true pine

Scotch fir and true pine both are nouns.

Word	Noun	Adjective	Verb	Adverb
Scotch fir	Yes	No	No	No
true pine	Yes	No	No	No

As nouns, true pine is a hypernym of Scotch fir; that is, true pine is a word with a broader meaning than Scotch fir:

Scotch fir: medium large two-needled pine of northern Europe and Asia having flaking red-brown bark
true pine: a coniferous tree

Other hypernyms of Scotch fir include pine, pine tree.

Scotch fir (noun)	true pine (noun)
medium large two-needled pine of northern Europe and Asia having flaking red-brown bark	a coniferous tree