Invasive SpeciesJapanese barberry

Berberis thunbergii
FOUND by JustAlfred
Cape Elizabeth, Maine
ID Questioned
Quality checked by Julia T
Peer reviewed by
Field Notes
On a very sunny, warm Thursday, our teacher asked us to go find and observe the invasive species, the Japanese Barberry, (Berberis Thunbergii). Our group went exploring along the woods and an old frog pond of Cape Elizabeth Middle School, which is to the right of the basketball courts. On the outside right corner of the fenced in area, we found about 3-4 bushes of the Japanese Barberry. If you squeezed the berry on the plant it would produce a very pungent smell. We could see the other groups taking pictures in the distance, we could hear other groups talking and yelling about their own species.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
One way to distinguish it from other berry bushes is by it’s bright red berries, which were found in groups of 9 or 10 berries on this particular bush. These bushes were also found closer to other trees and bushes. Once the berries are fully ripened they are a bright red color. They are about the size of a pencil tip, so about 1 centimeter.
Photo of my evidence.
The second way to identify the Japanese Barberry is by its thorns. The thorns on the Japanese Barberry are about the size of a fingernail, as you can see from the picture. Another thing to note is that the thorns have little black speckles on them.
Photo of my evidence.
As you can see here, the leaves are a green color. They have the shape of a oval with a point at the tip of the leaf. The leaves also felt very soft and dewy. We used someone's index finger to measure the leaf, because we measured the finger a couple of times to make sure it was accurate, and the leaf was about 3 to 2 ½ cm long.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Berberis thunbergii
Common name:
Japanese barberry
Count of individuals: 
Less than 1/4 covered
Fruit (plants)
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.593100 °
W -70.231800 °
Observation Site Information
A photo of our study site.
Upland - Field
Trip Information
Cape Elizabeth Middle School Lacrosse Fields
Trip date: 
Thu, 2016-10-06 08:15
Town or city: 
Cape Elizabeth, Maine
Type of investigation: 
Species and Habitat Survey
Habitat Observations
Species diversity: 
20 different species
Evidence of vectors: 
Dirt road
Walking trail
Fenced Space
Tree canopy cover: 
Between 1/4 and 1/2
Soil moisture: 


Careful JustAlfred,

You're looking at a few different species here, none of which look like Japanese barberry to me.

Check out the species cards for deadly nightshade and multiflora rose to see if those change your mind.

So glad you're out looking for invasive species! Plants can be very tricky to identify. Keep looking closely and honing your skills.

Good quality photos!!