- Fallopia japonica is an upright herbaceous perennial shrub reaching heights of 10 ft. (3 m). The semi-woody stem is hollow with enlarged nodes.
- Leaves are alternate, 6 in. (15.2 cm) long, 3-4 in. (7.6-10 cm) wide and broadly-ovate. Leaf tips are abruptly acuminate and the bases are truncate.
- Flowering occurs in late summer, when small, greenish-white flowers develop in long panicles in the axils of the leaves. Plants are dioecious (male and female flowers occur on separate plants).
- The fruit are papery and winged, containing shiny, black, three angled achenes.
- Ecological Threat
- Fallopia japonica commonly invades disturbed areas with high light, such as roadsides and stream banks. Reproduction occurs both vegetatively (rhizomes) and seeds, making this plant extremely hard to eradicate. The dense patches shade and displace other plant life and reduce wildlife habitat. This plant is native to eastern Asia and was first introduced into North America in the late 1800s.
- Global Invasive Species Database. 2011. Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission
- King County Department of Natural Resources and Parks Water and Land Resources Division
- Plant Conservation Alliance's Alien Plant Working Group
- USDA NRCS PLANTS
- USDA ARS GRIN