buttonwood vs plane tree

buttonwood and plane tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
buttonwood	Yes	No	No	No
plane tree	Yes	No	No	No

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

buttonwood: very large spreading plane tree of eastern and central North America to Mexico
plane tree: any of several trees of the genus Platanus having thin pale bark that scales off in small plates and lobed leaves and ball-shaped heads of fruits

Other hypernyms of buttonwood include platan, sycamore.

buttonwood (noun)	plane tree (noun)
very large spreading plane tree of eastern and central North America to Mexico	any of several trees of the genus Platanus having thin pale bark that scales off in small plates and lobed leaves and ball-shaped heads of fruits