Japanese tree lilac vs Syringa amurensis japonica

Japanese tree lilac and Syringa amurensis japonica both are nouns.

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

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

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

Other synonyms of Japanese tree lilac include Syringa reticulata.

Japanese tree lilac (noun)	Syringa amurensis japonica (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