Fishbone Cactus, Epiphyllum spp (10-12” Cutting)
Fishbone cactus, aka Rik Rak cactus.
I purchased this as the extremely vibrant pink flowered type, but I can't say for sure that is what it is as mine has not flowered yet. I expect flowers soon though as it is very mature.
I have also seen these referred to as the Orchid Cactus, but there are several species that are often called that.
(1) unroofed cutting. Although many of these do have aerial roots