Polygonum cuspidatum

Japanese Knotweed

Origin Of Species
Physical Description
Japanese knotweed is a perennial herb that generally grows between three and ten feet in height.  Its extremely sturdy stems are upright and hollow with oval leaves that reach between two and six inches in length and nearly five in width.  The greenish-white flowers appear in small clusters along the stems between August and September.  Obscure triangular seeds are dark brown.
Habitat And Distribution
Japanese knotweed is generally found along riverbanks, roadways, and hillsides along the northeastern and northwestern United States from New England to North Carolina and around California and Washington.
Location On Campus
Japanese knotweed is not known to be on campus, but is a common roadside weed throughout the Richmond area.
Negative Impacts
Japanese knotweed possesses extremely long and complexly branched rhizomes, which allow it to undergo vegetative reproduction readily.  Its rapid rate of growth results in dense, thick, resilient stands that effectively displace native plants, especially in fragile riparian ecosystems.
VDCR Invasiveness Ranking
Highly Invasive Species

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