periwinkle vs Vinca rosea

periwinkle and Vinca rosea both are nouns.

Word	Noun	Adjective	Verb	Adverb
periwinkle	Yes	No	No	No
Vinca rosea	Yes	No	No	No

As nouns, periwinkle and Vinca rosea are synonyms defined as:

periwinkle and Vinca rosea: commonly cultivated Old World woody herb having large pinkish to red flowers

periwinkle (noun)	Vinca rosea (noun)
edible marine gastropod	commonly cultivated Old World woody herb having large pinkish to red flowers
small edible marine snail; steamed in wine or baked
chiefly trailing poisonous plants with blue flowers
commonly cultivated Old World woody herb having large pinkish to red flowers