Ontario Wildflowers website

Japanese Knotweed
Fallopia japonica
(formerly Polygonum cuspidatum)

Japanese Knotweed (Fallopia japonica) Other scientific names: Polygonum cuspidatum

Family: Smartweed Family (Polygonaceae)

Flowers: Summer;  White;  5 parts (petals)

Habitat: Fields and Open Areas, Meadows, Roadsides, Thickets

Books: Newcomb's Wildflower Guide: 190   

Native/Non-native: Non-native

Origin and Meaning of Names:
 Scientific Name: japonica: of Japan, Japanese


See Also:
  •   Invaders: Japanese Knotweed, from The Monday Garden, by Sue Sweeney


Photographs: 51 photographs available, of which 9 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Japanese Knotweed (Fallopia japonica) flowers

Japanese Knotweed in bloom.

Japanese Knotweed (Fallopia japonica) flowers

Japanese Knotweed with lots of flowers.

Japanese Knotweed (Fallopia japonica) flowers

closeup view of Japanese Knotweed flowers.

Japanese Knotweed (Fallopia japonica) flwoers

Japanese Knotweed (Fallopia japonica) plant

Japanese Knotweed (Fallopia japonica) grove

A grove of close-growing Japanese Knotweed plants.

Japanese Knotweed (Fallopia japonica) shoot

A young Japanese Knotweed shoot in mid-May.

Japanese Knotweed (Fallopia japonica) seeds

Seeds.

Japanese Knotweed (Fallopia japonica) hollow stalk

The hollow stem.


Range map for Japanese Knotweed (Fallopia japonica)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)