Iris germanica or commonly known as purple flag or just iris (κρινάκι ή ίριδα), belongs to the Iridaceae family. One of its main characteristics is the beard of hair in the middle of the petal. It has beautiful flower that appears both in white and purple. The leaves and the rhizome contain irisin a substance that can cause irritanion of the digestive system. I saw those ones while hiking near Vradeto (Epirus) and the white one in my garden.
In ancient Greek mythology Iris was personification of the rainbow and a messenger.