Vinca major vs large periwinkle

Vinca major and large periwinkle both are nouns.

Word	Noun	Adjective	Verb	Adverb
Vinca major	Yes	No	No	No
large periwinkle	Yes	No	No	No

As nouns, Vinca major and large periwinkle are synonyms defined as:

Vinca major and large periwinkle: plant having variegated foliage and used for window boxes

Vinca major (noun)	large periwinkle (noun)
plant having variegated foliage and used for window boxes	plant having variegated foliage and used for window boxes