Posted: 24/02/2015 at 09:06
Vesuvius a cultivar of Lychnis x arkwightii, has never done more than a season for me either Verdun.
L. coronaria grey leaves, white or magenta flowers, don't last all that long but seed around.
Lychnis chalcedonica, Maltese Cross with the bright red flowers is truly perennial but for me that red and the shade of green in the leaves don't go well together.
My guess is that the one coming back every year is L. chalcedonica