The streamer (Anticlea derivata) is a moth of the family Geometridae. It is found in Europe, North Africa and Asia up to the Altai Mountains. The wingspan is 30–34 mm. The ground colour, is light brown or light grey or pink tints predominate. A narrow, dark lateral band is located near the base of the forewings. The basal region is limited by a slightly curved, blackish transverse band. A large dark triangle costal patch which becomes a jagged line is getting thinner towards the inner edge is an unmistakable pattern. The hindwings are brown-grey and show a faint cross line.