I think you hit the nail on the head.

I never see this in my area.

Thank goodness.

The plant I took the samples from appeared to be a large shrub/tree in itself, very woody.

Then I saw a 25ft tall Juniperus virginiana with a Celastrus scandens showing through the branches up to about 20 ft. of the tree. Couldn't tell if it was growing alongside the tree or if it was a vine. Now I know.

Thanks!

I've only occasionally seen this vine around here, 98% of the time it's the invasive Asian version and I'm always pulling seedlings of it from under where the birds sit.

I couldn't say if this is the native species or not, but it does show Celastrus scandens present and native all over Minnesota. Hope that's so.

We say it in several places.

The only good thing I noticed is it appeared to be winning the fight, growing up through an established bunch of Rhamnus cathartica. Although the C. s. was already going dormant for the season where the buckthorn will be green until November.

Here's the Red-cedar, appearing to be loosing the fight or so it seemed.

This has a key showing how to tell orbiculatus and scandens apart. The linked-to full descriptions also in turn have links to illustrations of each species.

Celastrus in Flora of North America @ efloras.org

Thanks, Embothrium.

The bike trail was a revamped railroad ROW, where the rails were removed, and asphalt paved. Those tend to be the places where nonnatives show up, for some reason. Maybe seeds or pollen hitchhike on trains?

But I definitely think the ones I saw were C. scandens although it sounds like they can easily hybridize with C. orbiculatus.