Jumpseed, Virginia knotweed. Native. Member of the Polygonaceae family. Jumpseed, Virginia knotweed reaches a height of 1-4 feet and grows in woodlands of the central and eastern United States. Its leaves are lanceolate/ovate in shape and alternate in arrangement along its stem. Raceme of the plant is long and sports small, white flowers that are widely spaced. Virginia knotweed is also known as Jumpseed because of its seed dispersion mechanism: pressing on the style of a mature seed causes it to pop off the plant. Blooms July-October.