pepper bush vs Clethra alnifolia

pepper bush and Clethra alnifolia both are nouns.

Word	Noun	Adjective	Verb	Adverb
pepper bush	Yes	No	No	No
Clethra alnifolia	Yes	No	No	No

As nouns, pepper bush and Clethra alnifolia are synonyms defined as:

pepper bush and Clethra alnifolia: shrub of eastern and southern coastal United States having beautiful racemes of spice-scented white flowers

Other synonyms of pepper bush include summer sweet, sweet pepperbush, white alder.

pepper bush (noun)	Clethra alnifolia (noun)
shrub of eastern and southern coastal United States having beautiful racemes of spice-scented white flowers	shrub of eastern and southern coastal United States having beautiful racemes of spice-scented white flowers