Nohandle, I've never seen seed offered for this plant. I even checked my wholesale sources. When I grew commercially, I propagated this plant by division, but that's not to say that it doesn't provide seed. Some plants aren't worth growing from seed when you can get 20-50 healthy divisions from one plant. When I wanted seed I would grow stock plants and collect my own. Some of these seed companies hold their seeds for years, and viability is poor. It's easy to get discouraged, because you think it's something you did wrong. That's why I collected as much of my own seed as possible.

Here is a link that might be useful: My Garden Travels