Invasive SpeciesGiant knotweed

Fallopia sachalinensis
FOUND by 18Fha
ID Questioned
Quality checked by Ms H
Peer reviewed by CB
Field Notes
It was a cold cloudy day when we went to Mackworth Island. It was around 10:00. The island was filled with tons of invasive species everywhere. The weather got progressively warmer as the day passed on, and in the morning, the plants were a little wet. We strolled around, looking for our invasive plants. We pretty much found all the plants we were assigned to. The forest part of the island had giant knotweed everywhere, and it was too much, so we helped the island by cutting them down, but it only helped a tad. On the beach, there was knotted wrack everywhere on the rocks. It was slippery and wet. The water extended far out, and it had steep hills going up into where the forest was. We started at that section and around 12:00 pm and ended our observations at 1:30. We found 13 green crabs, 6 were female and 7 were male. We also saw all kinds of periwinkles and I counted 82 of them around our section. We also saw a few invasive plants at the top of the steep hill made out of rocks. The crabs were under the rocks, where there was the perfect habitat for them. The water was close to our transect, but not too close. Our section was in the near left end of the transect, near the cliff. The knotted wrack made it hard to walk and there were shells underneath it. In all, there were too many invasive species that needs to be taken care of.
Supporting Evidence
Photo of my evidence.
This has a hollow stem like the Giant Knotweed
Photo of my evidence.
Like the Giant Knotweed, this has a zig-zag stem and also has knots where the leaves grow.
Photo of my evidence.
Like the Giant Knotweed, this plant grows 2-5 meters tall.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Fallopia sachalinensis
Common name:
Giant knotweed
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.687200 °
W -70.229700 °
Observation Site Information
A photo of our study site.
Coastal - Beach or dune
Trip Information
Mackworth Marine Transect Investigation
Trip date: 
Tue, 2018-10-09 07:36
Town or city: 
Type of investigation: 
Species Survey
Time of low tide: 
Wed, 2018-10-03 10:15


Dear 18hfa,

The characteristics you note in your description and evidence statement would be the same if what you were looking at was Japanese knotweed. How did you convince yourself that what you were seeing was giant knotweed instead? Did you make any measurements??

Please reply with your additional evidence.