I'm pretty sure that's Vinca minor, an invasive exotic. People call it periwinkle and plant it all over shady yards. It has escaped in lots of places and literally blankets the forest floor. I am battling it in part of my yard - I can see it advancing into the woods every year, despite my efforts.

Run for your life! That plant sends out runners underground like steel. If you chop up the roots, each part grows back into more and more plants. I worked like a dog to remove a 3 by 3 foot patch. I saw an ad for vinca minor that said routine mowing will make it come back thicker and stronger - as if that was a selling point. They sell it around here as a ground cover. I call it a ground hogger.

Here is a link that might be useful: vinca minor

Hey, I like those! We used to have a section of them next to our lawn at our last house in the woods. In the spring they looked very pretty.

We've got some small plants starting at the edge of our woods at our current house and I'm hoping they come along. It's in an area of our house where there's no landscaping and the ground cover that it can provide will be much nicer to look at than the bare ground that currently exists there.

Like them or not, they will take over your woodland. Once they're there, they are almost impossible to get rid of and they'll choke out just about everything else. Please don't let them escape your yard.