sourwood vs flowering tree

sourwood and flowering tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
sourwood	Yes	No	No	No
flowering tree	Yes	No	No	No

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

sourwood: deciduous shrubby tree of eastern North America having deeply fissured bark and sprays of small fragrant white flowers and sour-tasting leaves
flowering tree: any tree having seeds and ovules contained in the ovary

Other hypernyms of sourwood include angiospermous tree.

sourwood (noun)	flowering tree (noun)
deciduous shrubby tree of eastern North America having deeply fissured bark and sprays of small fragrant white flowers and sour-tasting leaves	any tree having seeds and ovules contained in the ovary