Apparently it's Epiphyllum, they area also called orchid or leaf cacti. It's not really a single plant but a species. Usually you can find the name of a plant or animal etc by searching for it on Wikipedia in your native language and then changing the language to English.

holy wiki says 1) Queen of the night, Night-blooming cereus, several genera and species of cactus 2)Queen of the night, Cestrum nocturnum, a woody evergreen commonly known as Night-blooming Cestrum

I think, it's epicactus.