I know basically nothing about Lychnis except that it's a perennial here, and I only know that because it's in the greenhouse where we keep the perennials.
I do like it, though. The color is very intense (more red and less orange in person), and there's something pleasing to me about how exact the geometry is. It's rare to see a pentagon that's that perfect. Opening the picture in a new window will make the details show up a lot better.