pitch pine vs pine tree

pitch pine and pine tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
pitch pine	Yes	No	No	No
pine tree	Yes	No	No	No

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

pitch pine: large three-needled pine of the eastern United States and southeastern Canada; closely related to the pond pine
pine tree: a coniferous tree

Other hypernyms of pitch pine include pine, true pine.

pitch pine (noun)	pine tree (noun)
large three-needled pine of the eastern United States and southeastern Canada; closely related to the pond pine	a coniferous tree
large three-needled pine of southeastern United States having very long needles and gnarled twisted limbs; bark is red-brown deeply ridged; an important timber tree