periwinkle

periwinkle, in zoology

periwinkle, any of a group of marine gastropod mollusks having conical, spiral shells. Periwinkles feed on algae and seaweed. They are found at the water's edge; out of water, they resist drying by closing themselves into the shell with a horny plate. The edible European species, called the common periwinkle, has become well established on the Atlantic coast of North America. About 12 other species are found on rocky beaches of both the Atlantic and the Pacific coasts. Periwinkles are classified in the phylum Mollusca, class Gastropoda, order Mesogastropoda, family Littorinidae, genus Littorina.

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periwinkle, in botany

periwinkle, in botany: see dogbane.

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periwinkle

In botany, any of various plants of the genus Vinca of the dogbane family. The lesser periwinkle (V. minor), which has small lilac-blue flowers, is a dependable, trailing, evergreen perennial that is native to Europe and has become widespread over much of eastern North America. The greater periwinkle (V. major), with larger leaves and larger purplish-blue flowers, is native to continental Europe and has become naturalized in England. Alkaloids derived from the periwinkle plant have had some success in inhibiting cancer growth.

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periwinkle

Periwinkles (Littorina)

(credit: Jane Burton—Bruce Coleman Ltd.)

In zoology, any of some 80 species (family Littorinidae) of widely distributed, chiefly herbivorous shore snails. Periwinkles are usually found on rocks, stones, or pilings between high- and low-tide marks. The common periwinkle (Littorina littorea), the largest northern species, may grow to 1.5 in. (4 cm) long. It is usually dark gray and has a solid spiral shell. Introduced into North America c. 1857, it is now common on Atlantic coasts. All periwinkle species are a favourite food of many shorebirds.