silver bell vs flowering tree

silver bell and flowering tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
silver bell	Yes	No	No	No
flowering tree	Yes	No	No	No

As nouns, flowering tree is a hypernym of silver bell; that is, flowering tree is a word with a broader meaning than silver bell:

silver bell: any of various deciduous trees of the genus Halesia having white bell-shaped flowers
flowering tree: any tree having seeds and ovules contained in the ovary

Other hypernyms of silver bell include angiospermous tree.

silver bell (noun)	flowering tree (noun)
any of various deciduous trees of the genus Halesia having white bell-shaped flowers	any tree having seeds and ovules contained in the ovary