Vinca major vs periwinkle

Vinca major and periwinkle both are nouns.

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

As nouns, periwinkle is a hypernym of Vinca major; that is, periwinkle is a word with a broader meaning than Vinca major:

Vinca major (noun)	periwinkle (noun)
plant having variegated foliage and used for window boxes	edible marine gastropod
	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