catalpa vs bean tree

catalpa and bean tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
catalpa	Yes	No	No	No
bean tree	Yes	No	No	No

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

catalpa: tree of the genus Catalpa with large leaves and white flowers followed by long slender pods
bean tree: any of several trees having seedpods as fruits

catalpa (noun)	bean tree (noun)
tree of the genus Catalpa with large leaves and white flowers followed by long slender pods	any of several trees having seedpods as fruits