Roselys (formerly HMS Sundew) was one of the nine Flower-class corvettes lent by the Royal Navy to the Free French Naval Forces.

She served as a naval escort in World War II.

However, the French for sundew, rosée du matin (literally "morning dew"), was considered unsuitable and the girl's name Roselys ("Rose-Lilly") was used instead, perhaps with the intention of linking the English Tudor rose with the French fleur-de-lys.

[4][5] She was part of Convoy QP 13, and rescued 179 survivors on 5 July 1942 when several ships ran into naval mines.

[6] Roselys was one of nine Free French escort vessels which supported the Normandy landings on and after 6 June 1944, protecting the movement of landing and supply ships across the English Channel.