Caltha palustris

[cc]

Caltha palustris, some kind of water marigold and Nopalxochia phyllamthoides, also called German empress or pondlily cactus. Hoping some of you have these two plants, they
are so pretty but nurseries over here don't have them.

 

[marla]

Marsh Marigolds are common here wild in most any marshy area (spring blooming), they can be located at most nurseries carrying pond plants, however the picture you have seems to have a double flower, more common is the single which looks more like a buttercup.  As for the other it looks a lot like a Christmas Cactus, but by the name I think maybe an Orchid of some type, I would think it would be tropical, and if a cati not wanting to have wet feet in a pond.  Maybe Joyce will give you a better answer.

[LeeAnne151]

single blooming Marsh Marigold is common here in pond plant sections at nurseries and I have one. Love that double bloom, have never seen that one here nor the white one.

The orchid cactus is not common here but I know that there are pond forum members who have them and who might share a segment. I killed mine that I received   greenhouse wasn't warm enough or sunny enough and it rotted.

[JoshS]

Caltha palustris 'Flore Plena' is the name of the double Marsh Marigold.  I'm sure I've seen it offered for sale in the US, but can't remember where.