I don't think it's a lewisia,maybe do a net search on claytonia?

I'd think definitely not a lewisia, and it looks soooo familiar!

Maybe a Saponaria?

Montia parvifolia?

My money's on a Saxifrage.

In the meantime, the L. cotyledon I found at Home Depot is blooming abundantly. I'm amazed. There are two types. Two look like the species, the other specimens are the "Sunset Strain" and are larger rosettes. But the species Lewisia is gorgeous in blossom. It was forced to bloom by the nursery in February, but now that it is outside in alpine containers, it is blooming again, and with larger and more flowers than the February flowering.

My guess it is a Talinum, not sure which species.