AKA Epiphyllum chrysocardium. Photos showing the spiny ovary, which is one of the reasons this was moved from Epiphyllum to Selenicereus.
It's a little too cold in winter here in coastal Southern California for this plant. It looks badly beaten up in Spring, and there is considerable dieback of stems. But it does flower when large enough.
Selenicereus = Moon Cereus (candle)
chrysocardium = golden heart
I am away from my desktop. It will be a while before I can rotate the images properly.
Blanco is a 4-year-old Giant Schnauzer I began fostering 3 weeks ago. He weighs 95 pounds / 43kg. He got his name, which means "white", because he was the only puppy in his litter having a few white hairs scattered in the shiny black coat. He's sitting under the basket with the Selenicereus. There is a standard 1 quart/liter spray bottle for scale.