Coarse emergent aquatic to terrestrial herbs .
Plants are highly plastic depending on environmental conditions.
Swamp smartweed and pale smartweed are widespread natives of North America that typically grow on the edges or in ponds, marshes, lakes, streams, and areas subject to seasonal flooding or periodic standing water. In natural areas they are a desirable component of the flora. Plants provide cover for wildlife, and the seeds are an important food source for many species of songbirds, waterfowl, and mammals. However, these species sometimes invade rice fields, pastures, orchards, and irrigated crops, and stands of emergent plants can impede the flow of water in irrigation ditches, canals, and drainage areas. Erect to spreading terrestrial summer annual , to 1 m tall.