Dianthus longicalyx

When I first met this plant 20-odd years ago, it was called Dianthus superbus. It kind of is superb. At least it's spectacular. There were multiple collections of it made in Korea in 1984. We have a problem with keeping them discrete: it's a short lived perennial, almost an annual and it moves about in the garden. It still wanders around in the beds adjoining the parking lot steps. I occasionally see it for sale as a plant. If you like it seeds are really the way to go.