New plants....Rosularias

I recently picked up two plants labeled Rosularia chrysantha and R. rechingeri.

Promethum (formerly Rosularia) chrysantha

Rosularia chrysantha is a lovely little plant I grew in a trough for several years, but which didn't survive last winter for some reason. . So I jumped at the chance to get another specimen. Rosularia chrysantha is a neat little rosette-forming species which a quick Google search tells me is native to Turkey. It's in a four-inch pot. My previous specimen never did bloom, maybe this one will...

Promethum (formerly Rosularia) rechingeri

This is R. rechingeri. A new species for me, we will see how cold hardy it is here. Also native to Turkey and growing in a 4 inch pot. Does anyone have experience growing this species outdoors in zone 6 or lower?

Update: In trying to get these IDs confirmed, I have learned that these two Rosularias have been moved into the genus Prometheum. I have been unable to find much  info about this genus on the internet so far..Anyone have any experience with these??