Lynn,
That photo was taken at the Leach Botanical Garden's rock garden area just yesterday.
Alex,
There were a number of what I took to be seedlings around, they all had an extremely flat rosette form. Sounds like we've solved the mystery, thanks for your expertise! It's a very interesting plant, I'd love to give it a try in my own garden but have never seen it offered for sale, perhaps I'll peruse the internet for it when I get the chance.
-Sol