Periwinkle

Periwinkle is a common name that applies to several very different things. In zoology it refers to small sea snails of the family Littorinidae, especially Littorina littorea, known as the common periwinkle. In horticulture it denotes two evergreen creeping or climbing plants in the genus Vinca, commonly grown as groundcover. The name is also used for a pale bluish‑purple color named after the flower.

The common periwinkle (Littorina littorea) is a small to medium-sized marine snail that inhabits the intertidal zone on rocky shores along the Atlantic coasts of Europe and, after introduction by humans, North America. It is an herbivore that grazes on various algae growing on rocks. The shell is typically brown or olive with darker bands and has a distinct aperture and an operculum, which closes the shell when the animal withdraws.

Periwinkle plants include Vinca minor and Vinca major. They are evergreen, creeping or trailing vines with glossy, opposite leaves and blue to violet flowers, sometimes white. They are widely cultivated as groundcovers in shade and woodland gardens and can tolerate a range of soils. In some regions, planted populations spread beyond gardens and may be invasive. All parts contain alkaloids and can be toxic if ingested by animals or humans.

The color periwinkle is a pale purplish-blue shade, intermediate between blue and violet. It is named after the flower and is used in cosmetics, fashion, and interior design.