Platyedra subcinerea, the mallow groundling or cotton stem moth, is a moth of the Gelechiidae family. It is found in most of Europe. It is an in introduced species in North America, where it has been recorded from New England and California. The habitat consists of wet meadows, marshes and gardens. The larvae feed on Parietaria officinalis, Urtica species, Althaea officinalis, Lavatera thuringiaca and Malva sylvestris.