Polygonum pensylvanicum, commonly known as Pennsylvania Smartweed is a native annual forb.
This plant is an excellent wildlife food plant, especially for waterfowl. Twenty species of ducks, geese, bobwhites, mourning doves, ring-necked pheasants, and four species of rails, as well as 30 nongame birds, eat the seeds. Dense stands provide cover for young waterfowl, marsh birds, and wintering pheasants. Plants and/or seeds are eaten by white-footed mice, muskrat, raccoons, and fox squirrels. Numerous species of beetles, flies and bees pollinate this plant. several turtles feed on smartweeds (probably the foliage to a minor extent); this includes such turtles as the Snapping Turtle, Painted Turtle, Eastern Box Turtle, and Slider.
Livestock usually avoid the foliage of Pennsylvania Smartweed and most other smartweeds because their leaves are somewhat bitter and peppery.
The preference is full or partial sun, moist conditions, and rich loamy soil. Standing water is tolerated if it is temporary. This robust plant is rather weedy and easy to grow.
Habitats include wet prairies, prairie swales, swamps, low areas near ponds or rivers, edges of marshes, degraded seasonal wetlands, abandoned fields, low areas along railroads, roadside ditches, vacant lots, fence rows, and waste areas. This annual plant thrives on the reduced competition resulting from disturbance.