There is a guy on fleabay from Brooklyn who sells marsilea. He sells it as M. minuta - but it is actually M. hirsuta. I got mine from him - and the plants were great quality. I recently had a mini-melt of my carpet (too thick maybe?) - and I have some promised out to others - so I can't spare any right now.
Al has M. minuta IIRC
Can you PM me his name or his link? I am not getting any results on Ebay. Thanks...