Syringa amurensis japonica vs Japanese tree lilac

Syringa amurensis japonica and Japanese tree lilac both are nouns.

Word	Noun	Adjective	Verb	Adverb
Syringa amurensis japonica	Yes	No	No	No
Japanese tree lilac	Yes	No	No	No

As nouns, Syringa amurensis japonica and Japanese tree lilac are synonyms defined as:

Syringa amurensis japonica and Japanese tree lilac: small tree of Japan having narrow pointed leaves and creamy-white flowers

Other synonyms of Syringa amurensis japonica include Syringa reticulata.

Syringa amurensis japonica (noun)	Japanese tree lilac (noun)
small tree of Japan having narrow pointed leaves and creamy-white flowers	small tree of Japan having narrow pointed leaves and creamy-white flowers