I have a cross AnTec made yrs ago, Robinsonianum using dianthum rather then parishii. At the time, the two plants were considered the same just dianthum was a different form of parishii. I'm sure the cross doen't carry the same name now. I have one plant left of this cross and it has never gotten big enough to bloom. Poor growth habits; weak grower, floppy leaves and proned to rot. I had a flask, sold a few and lost most to rot.
Speaking of rot or damp off, does anyone else have this problem with straight P.dianthum, I do. I lost one plant and one small outcross seedling suffers from damp/wetspots on the area just at the base of the plant.