Invasive SpeciesOriental bittersweet

Celastrus orbiculatus
FOUND by Yoga CatastropheP4
Cape Elizabeth
ID Confirmed
Quality checked by Yoga CatastropeP4
Peer reviewed by Meredith
Field Notes
We went outside on a typical fall day for Maine. It was mid October and the temperature was neither warm or cold. The bittersweet was, if not the most, one of the most dominant species in the field. We found large clusters of it in numerous locations, wrapped around trees and shrubs. It had lots of red berries with yellow skins on them, which is expected from oriental bittersweet this time of year. The leaves were alternating in position, oval in shape, and toothed around the edges.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
We know that this species is oriental bittersweet, because it has bright red berries with yellow skin all over it- a distinctive trait of oriental bittersweet. When we searched for this species it was mid October, so some of the green leaves that you would see in the summer are gone. These berries are present everywhere on the oriental bittersweet, which is a trait that differentiates it from American Bittersweet, a commonly confused relative.
Photo of my evidence.
Another reason why we think that we found oriental bittersweet is because of the length and texture of the stem. The stems were nearly twenty meters in length and surviving all over the location. They were were wooden, bumpy and brown, which is what they are supposed to look like if they're of a certain age. The bittersweet we found had brown stems which would mean it was an older plant.Though we don't know how to determine the exact age, it would make sense that most were older because of certain defining traits such as size, color, and how widespread they were through the field.
Photo of my evidence.
We think this is oriental bittersweet because the leaves have toothed edges and were arranged in an alternating pattern. The leaves also appeared to have an oval like shape which is another trait of oriental bittersweet. The leaves we found were around 8 cm long and a lot of the leaves had pointed tips. Some of the green leaves had fallen off, because they thrive in July and August, which had ended recently enough so that some traces of this seasonal characteristic remained.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Celastrus orbiculatus
Common name:
Oriental bittersweet
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.593170 °
W -70.232470 °
Observation Site Information
A photo of our study site.
Upland - Developed areas
Trip Information
CEMS Grounds 2015 #2
Trip date: 
Tue, 2015-10-27 10:49
Town or city: 
Cape Elizabeth
Type of investigation: 
Species Survey


Hi Yoga CatastropheP4 (love the name),

I really love your sketch! You did a wonderful job capturing the way the fruits look when opened. Good observation to boot with lots of good evidence to back up your claim and rule out American bittersweet.

Thanks for sharing and happy observing,