Last spring I bought three ferns called 'Arbor Vitae Fern' at a local nursery. I was attracted to them because the foliage was very interesting - it actually looks like an arbor vitae bush! The tag said these low-growing ferns were hardy, but I'm always skeptical of exotic looking plants I haven't seen in other gardens in the region, so I planted them next to the bench in my shade garden and figures they would probably not emerge this spring, but I would enjoy them for one season.
I believe these reproduce by spores although they're not a true fern. I saw some references for Selaginella braunii in the DG guides. Lucky you - they're hardy to about zone 6. I had wanted some a few years back but didn't think they'd survive here.
We had an exceptionally mild winter, so it could be a fluke. I was afraid they would not be hardy (I really get angry when I discover a local nursery offering something that is not hardy in my zone) and I was willing to chalk them up to experience, but I'm glad they survived. I wish they would spread throughout the shade garden, but if they aren't hardy, that would just add to my disappointment.
I think I read that they are slow-growing so doubtful they'd spread like, say, ostrich ferns. Perhaps your bench there is offering some protection. Maybe after another growing season of settling in, they might be able to survive a colder winter???
They do pretty well for me here in GA. I've seen them around enough that I thought they might be native here but, spurred by your questions, I looked it up and it is not native here though it has naturalized.
Doug - you are the enabler. :) Actually, I did look around at a nice nursery up in Holland, MI over the weekend but didn't see any. I was thinking they might have them since they're a whole zone warmer than me. Thanks for those links!