I think it is perhaps Silene virginica.

Yes, that looks exactly right. Thank you. Very cute with the notched petals which S. regia doesn't have. I see it requires a more dry environment, maybe drier than I have here in Massachusetts but I think I'll get some seed and give it a try.

S. virginica blooms in Spring, S. regia in the fall.

Try Using PlantNet. It is a plant identifier app that tells you about the plant after just taking a picture.