magnolia vs sweet bay

magnolia and sweet bay both are nouns.

Word	Noun	Adjective	Verb	Adverb
magnolia	Yes	No	No	No
sweet bay	Yes	No	No	No

As nouns, sweet bay is a hyponym of magnolia; that is, sweet bay is a word with a more specific, narrower meaning than magnolia:

magnolia: any shrub or tree of the genus Magnolia; valued for their longevity and exquisite fragrant blooms
sweet bay: shrub or small tree having rather small fragrant white flowers; abundant in southeastern United States

magnolia (noun)	sweet bay (noun)
any shrub or tree of the genus Magnolia; valued for their longevity and exquisite fragrant blooms	shrub or small tree having rather small fragrant white flowers; abundant in southeastern United States
dried bark of various magnolias; used in folk medicine