Above: Terrestrial Swamp Smartweed on the shore of Lake Wingra in Vilas Park in Madison, Wisconsin. (9/02/21).
Terrestrial Swamp Smartweed - Persicaria amphibia (var. emersa long spike)
Swamp Smartweed is a native flowering plant in the knotweed family that grows in meadows, shallows, water less than 7' deep and in sediment soil.
Swamp Smartweed is both aquatic and terrestrial. The terrestrial plant is 1-3' tall.
Flowers are bright pink to red with 5 tepals arranged in a dense, spike-like, terminal cluster.
Blooms June-Sept.
Other Names: Longroot smartweed, water knotweed, water smartweed, water heart's-ease and amphibious bistort.
Above: Swamp Smartweed leaves are up to 8 inches long and 3 inches wide, and alternate.
For more information on Terrestrial Swamp Smartweed, visit Wikipedia.
Or, visit the UW-Madison Wisconsin State Herbarium website page about Terrestrial Swamp Smartweed - Persicaria amphibia.
Terrestrial Swamp Smartweed
Persicaria amphibia (var. emersa)
Above: Terrestrial Swamp Smartweed on the shore of Lake Wingra in Vilas Park in Madison, Wisconsin (9/2/21).
Above: Terrestrial Swamp Smartweed on the shore of Lake Wingra in Vilas Park in Madison, Wisconsin (9/11/21).
Above: 1796 Swamp Smartweed illustration by Jacob Sturm.
Above: 1918 Swamp Smartweed.
Above: Swamp Smartweed specimen collected near the Town of Eagle in Waukesha County on September 13, 1938.