Fleur-de-lis...

Iris pseudacorus: (yellow flag, yellow iris, water flag) is a species in the genus Iris, of the family Iridaceae. It is native to Europe, western Asia and northwest Africa. Its specific epithet, meaning "false acorus," refers to the similarity of its leaves to those of Acorus calamus, as they have a prominently veined mid-rib and sword-like shape.
(Wikipedia)