Friday, November 5, 2010

Invasive Species -- Bittersweet

The Indiana DNR has been spending a lot of time pulling weeds at the Indiana Dunes.

They pull cattails out of the bog. Even though cattails are indigenous to Indiana they do not belong in the bog. They change the landscape of the bog pushing out native plants. Once the cattails are removed, sedges native to the area of the bog are planted. We have so little bog areas left like those at the Dunes. The bogs contain unique ecosystems that harbor endangered plant and animal species.

 Another of the invasive species is a plant that makes it into fall flower arrangements is bittersweet. This invasive is not indigenous to Indiana and is very invasive. The DNR worked hard for a couple of years pulling this plant out of the Dunes and it is now finding it's way back into the ecosystem. Plants like the bittersweet choke out trees and native plants that native animals, birds, and butterflies need to survive.       


  1. Is that Oriental bittersweet (Celastrus orbiculatus Thunb.) or the American bittersweet (Celastrus scandens)? My understanding is that scandens is native and not invasive. Moreover, the native species is actually in decline across its range. My guess is that you were seeing orbiculatus, which produces clusters of fruits along the entire stem, whereas the native only produces seeds on a small number of clusters near the tip of the vine.

  2. You're absolutely right. It is sometimes difficult to identify between our native species and the oriental type. They do hybridize making it even more difficult to tell them apart.

    I believe pictured is the oriental variety. The berry clusters are in the leaf axils along the length of the stem.

    While both varieties can crowd out trees the oriental type grows faster and more prolific, making it more difficult to control.

    A good source of information on this can be found at