Knotweed is an herbaceous perennial originally discovered in Virginia and is in the knotweed (Polygonacea) family. It is native to the U.S. along the east coast except for Maine, west toward eastern Texas, south to the Gulf Coast and north to southern Minnesota.
Plants can be 2-3 feet tall with a clumping arching habit. The sparse tiny white to greenish-white flowers bloom on long, slender stems in mid to late summer. Even though the flowers are not showy, they attract butterflies and bees. The variegated cultivars such as Painter’s Palette are grown for their showy foliage.