Imposter plant in my raspberries- ideas?

Hi - I’m in New England. The last couple of years,
An imposter plant grew amongst my raspberries. It looked remarkably similar. The first year I left it because I thought they were primocanes. But the stems are smooth - no thorns, they bear a lot of white flowers, the leaves are similar to the raspberry ones but fewer ruffles. I spent a lot of time just staring at them to figure out if they were raspberries or imposters. Finally I pulled them all out - they were really taking over - and while I didn’t get a great crop at least some of my yellow raspberries survived. I have searched online but I only find responses about fruiting plants or “don’t worry it’s a primocane” (it’s not). Any idea what it is?

I wish I had pics - I’ll take some if it comes back next year.

Jennifer

Welcome to Permies, Jennifer!

Sounds like a wild blackberry. They were all over the place when I lived in Vermont, but ours had thorns.
Did it look like this?

It's possible that you have a weed or wild relative, but the fact that it doesn't have thorns makes me doubt that. It's possible that the place you bought from accidentally mixed a thornless variety in with yours. Another possibility is that you might have a mutation or a sport that developed from your plants. I'd be inclined to transplant it somewhere and keep an eye on it.