Ammannia auriculata, commonly known as eared redstem, is a species in the family Lythraceae that is found in tropical and subtropicalt areas around much of the world. The slender and erect herb typically grows to a height of 5 to 40 centimetres (2 to 16 in). It blooms in March producing orange-purple flowers. In Australia the species is found along the swampy margins of streams in a few scattered areas of the Kimberley and Pilbara regions of Western Australia extending into the Northern Territory and Queensland where it grows in black loamy soils.