Invasive SpeciesJapanese knotweed

Fallopia japonica
FOUND by Gharial
ID Confirmed
Quality checked by Alpaca
Peer reviewed by Shark
Field Notes
We have been working at William S. Cohen. We think we have found a Fallopia japonica, or Japanese Knotweed. We have made a rubbing and a few sketches of the plant. The whole plant was around 2 meters tall and was growing quite far along the fence.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
The leaves are about five inches long at maximum. The stems which hold the leaves are colored green, and also give way to the smaller stems which the flowers are on. The leaves were slightly smaller than my hand, and had the shape of the plant we had studied. The leaves alternated along the stem, and had an alternate arrangement. The edge was completely smooth. We know that it isn't giant knotweed because of the small size of the leaves, which are quite a bit smaller than a hand.
Photo of my evidence.
There were small flowers in bunches of 50 to 100 flowers live on orange-white or orange-green stems. The flowers were each about the size of a capital O, and grew with five small white petals. A long pistil protruded out of the center of the flower. The flower stems were usually a bit bigger than your fist.
Photo of my evidence.
It has hollow bamboo-like shoots supporting the whole thing. The shoots have solid, swollen joints in between. The colors vary from green to brown. The sides had concave or convex bumps which allowed them to fit into each other at the joints.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Fallopia japonica
Common name:
Japanese knotweed
Count of individuals: 
Flower (plants)
Vegetative structures (plants)
Pollinators (plants)
Sampling method: 
Quadrat (user-placement)
Photo of our sampling method.
Place Studied
We’re sorry, JavaScript is required to view the map. If JavaScript is you may wish to upgrade to a newer browser in order to view this map.
Map this species
N 44.811199 °
W -68.755709 °
Observation Site Information
A photo of our study site.
Upland - Developed areas
Trip Information
Cohen School grounds
Trip date: 
Wed, 2018-09-12 09:48
Town or city: 
Type of investigation: 
Species and Habitat Survey
Habitat Observations
Species diversity: 
5 different species
Evidence of vectors: 
Paved road
Tree canopy cover: 
Between 1/4 and 1/2
Soil moisture: 


Very high quality photos. You have great descriptions as well.

Are there any invasive species which originated from places like the bottom of the ocean? We were wondering about this, since this would mean that the species isn't native to any country. Then, no matter where that plant lives on land, it would be invasive.