pond pine vs pine tree

pond pine and pine tree both are nouns.

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

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

pond pine: large three-needled pine of sandy swamps of southeastern United States; needles longer than those of the northern pitch pine
pine tree: a coniferous tree

Other hypernyms of pond pine include pine, true pine.

pond pine (noun)	pine tree (noun)
large three-needled pine of sandy swamps of southeastern United States; needles longer than those of the northern pitch pine	a coniferous tree