Fallopia japonica, Japanese Knotweed, Japanese bamboo, Mexican bamboo, Japanese fleeceflower, crimson beauty
Description: herbaceous perennial
Place of origin: temperate east Asia
Urban habitat: commonly found in low-lying wet areas, vacant lots, rubble dumps, drainage ditches, along railroad tracks, waterways, and roadsides; tolerates high temperatures, high salinity, and drought; thrives in full sun but can tolerate shade; can grow in compacted soil.
Ecological function: disturbance-adapted fast growing colonizer; erosion control on slopes, stream and river bank stabilization; soil building on degraded land.
History: Polygonum cuspidatum was introduced into North America as an ornamental plant in the 1870s and was sold in nurseries through 1910. It escaped cultivation and is now found in nearly all US states and in parts of Canada, where it is widely considered a noxious weed. The roots contain the anti-oxidant compound resveratrol, said to promote longevity. It has been used medicinally in its native habitat for treatment of burns, boils, cuts, fevers, poisonous snakebites, appendicitis, hepatitis, and menstrual irregularities. Extracts of the plant have shown to contain antitumor properties. A yellow dye can be obtained from its root. The plant is a potentially excellent source of biomass energy. Native American Cherokee consumed its cooked leaves as a vegetable.