Iva frutescens is a species of flowering plant in the aster family known by the common names Jesuit's bark, bigleaf marsh-elder, and high-tide bush. It grows in coastal eastern North America from Nova Scotia down the eastern coast and along the Gulf Coast to Texas. This species' position in the malophe front line of waterway erosion. It sometimes grows on substrate that has been dredged and laid out along the edges of waterways. This species provides habitat for salt marsh animals such as the marsh wren.