Platyedra subcinerea, the mallow groundling or cotton stem moth, is a moth of the family Gelechiidae.

[2] It is an in introduced species in North America, where it has been recorded from New England and California, and has also been introduced to New Zealand.

[3][4] The habitat consists of wet meadows, marshes and gardens.

[5] The larvae feed on Parietaria officinalis, Urtica species, Althaea officinalis, Lavatera thuringiaca and Malva sylvestris.

This article on a moth of the subfamily Apatetrinae is a stub.