Invasive SpeciesJapanese knotweed

Fallopia japonica
FOUND by saddleback
ID Confirmed
Quality checked by manyeyes
Peer reviewed by
Field Notes
We are happy because we saw lots of biodiversity, in our environment. In the environment, there were twigs, pine cones, stray leaves, and a lot of ferns. There was a small stream that wasn't flowing, fallen trees, and standing evergreens. There was a lot of Japanese Knot weed, in our environment. In our specific quadrat, there was Japanese Knot weed, a fern, lots of leaves, and some twigs and sticks. We had a couple creepy crawlys moving around in it. There were some mosquitos, and a few little unidentified bugs. We saw a couple of holes in the quadrat that could have been made by some animals or bugs. We saw lots of biodiversity in our quadrat. 10 different species. So far we havn't figured out if land use effects biodiversity, which was our question. The habitat however was full of biodiversity, and we were very happy with what we found.
Supporting Evidence
Photo of my evidence.
The leaves are oval and have smooth edges. They are really round but they are not that long. They look just like the leaves on the identification card.
Photo of my evidence.
The stem is long and hollow and the leaves zig-zag off it. It had lots of leaves but they all looked the same. The stem was green and looked like the stem from the card.
Photo of my evidence.
It is tall and has a REALLY long stem. It was taller than everyone in the group and it had at least 2 feet taller than Ryan and Zach.
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: 
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 43.793110 °
W -70.419030 °
Observation Site Information
A photo of our study site.
Upland - Forest
Trip Information
Pleasant River Site 2
Trip date: 
Tue, 2009-09-22 20:56
Town or city: 
Type of investigation: 
Species and Habitat Survey
Habitat Observations
Species diversity: 
10 different species
Evidence of vectors: 
Walking trail
Tree canopy cover: 
Between 1/2 and 3/4
Soil moisture: 


good job at sighting this rare plants.

Well you found Japanese Knotweed...once I knew what it was I haven't been able to stop seeing it! Well done Saddleback. Your photos and evidence statements clearly show that you have found this invasive species. Your second photo evidnece statement says that the leaves "zig zag" off the stem...I am curious what that looks like close up.

I like that even though you only found one plant in your quadrat you stated that there was a lot of it in your surroundings in your Field Note. Do you think that the stand of Japanese Knotweed will grow over time? Do you think this will affect the biodiversity in this habitat?

Great job folks!!

What a cool and creative idea to use your teammates (with faces well-hooded!) as your scale for showing and proving how tall the knotweed is!

Thanks for looking for invasive Japanese knotweed. How do you think that having an invasive species in your area will affect the biodiversity over time?