| |
 Appearance:
Shrub-like, arching, perennial forb,
over 10' high, reddish-brown stems, smooth, stout, hollow, swollen
at the joint where the leaf meets the stem. Leaves:
Alternate, broadly oval, and pointed at the tip, about 6" long, 3-4" wide.
Flower: Greenish-white, branched clusters which grow from leaf axils near
the end of stems, blooming in late summer. Fruit: Small winged, with
triangular, shiny, very small seeds. Root:
Long, stout rhizomes allow the plant to spread vegetatively as well. |
Japanese knotweed spreads
primarily vegetatively to form dense thickets that suppress native
vegetation. It can pose a significant threat to riparian areas, such
as disturbed stream sides and other low lying areas, where it can
rapidly colonize. It tolerates full shade, high temperatures, high
salinity and drought. Japanese knotweed currently occurs from Maine to Minnesota
and south to Louisiana, scattered in Midwestern and western states.
It was introduced to the U.S. in the late 1800s for ornamental purposes
and erosion control. |
 Plant
Conservation Alliance: Alien Plant Working Group www.nps.gov/plants/alien/fact
The Nature Conservancy Element Stewardship Abstract |
 |
|
