This is one of the most variable of the geometrids both in size (wingspan 32-39 mm) and colour. The basal and terminal areas of the forewings are marked with fascia separated by a large plain area in the middle, but the colouration of all these areas is confusingly variable from white to black with various grey, brown and reddish tones in between. The hindwings, though, are always pale grey marked with faint fascia. One or two broods are produced each year and the adults can be seen in any month from May to November . The species flies at night and is attracted to light. It is also attracted to nectar-rich flowers and sugary foods which is fairly unusual for the family.
Chinery, Michael Collins Guide to the Insects of Britain and Western Europe 1986 (Reprinted 1991)
Skinner, Bernard Colour Identification Guide to Moths of the British Isles 1984