HMS Periwinkle was a Flower-class corvette, built for the Royal Navy during the Second World War, and was in service in the Battle of the Atlantic. In 1942 she was transferred to the United States Navy as part of the Reverse Lend-Lease arrangement and renamed USS Restless, one of the Temptress-class gunboats. With the end of hostilities she was returned to the Royal Navy and sold into mercantile service.

The American Flower-class corvettes were those ships of the Royal Navy's Flower class built for, or operated by, the United States Navy during World War II. These were ten ships of the original Flower class, known as the Temptress class in US service, and fifteen Modified Flowers, as the Action class. In US service they were classified as Patrol Gunboats (PG).