• Latin Name: Polygonum Argyrocoleon
  • Latin Family Name: Polygonaceae
  • Common Name: Silversheath Knotweed
  • Other Names: Persian knotweed

Origin:
Native to southwest Asia, but it has become naturalized in the southwest United States and Mexico.

Biology:
Annual plant with very similar biology to Prostrate Knotweed. Although it is an annual, and propagates by seeds, the seeds may germinate in late fall, and plants may be present in the winter and even flower then.

Identification:
Distinguished from prostrate knotweed by its more erect growth and longer, rose-colored flower spikes. Mature plant grows up to 24 inches tall. Wiry stems have many branches. Leaves similar to prostrate knotweed as small, oval, and without hairs, but with a dull, light green appearance. At the base of the leaf stem a conspicuous silvery sheath wraps around the stem. Flowers are small, pinkish, and borne on short stalks in small clusters that grow off of the flower stems at the top of the plant. Flower stems may be up to 1 foot long.

Characteristics Important to Control:
Less common than prostrate knotweed, but may infest the same kinds of conditions – roadsides, waste areas, landscape, orchards, vineyards, and other cultivated cropland.