There are a number of different cactus species sold as "Christmas cactus," including Schlumbergera opuntioides, Schlumbergera kautskyi, and Schlumbergera microsphaerica.
Christmas | A Christmas Carol | Christmas Eve | Christmas Island | Christmas music | Christmas tree | A Christmas Story | Have Yourself a Merry Little Christmas | Christmas Oratorio | How the Grinch Stole Christmas | How the Grinch Stole Christmas! | Christmas lights | National Council for the Conservation of Plants and Gardens | Mickey's Christmas Carol | flora (plants) | The Nightmare Before Christmas | Merry Christmas Baby | Last Christmas | I'll Be Home for Christmas | Christmas lights (holiday decoration) | Christmas card | All I Want for Christmas Is You (Mariah Carey song) | All I Want for Christmas Is You | Father Christmas | Christmas in July | A Charlie Brown Christmas | The Christmas Attic | Rockin' Around the Christmas Tree | National Lampoon's Christmas Vacation | Julie Christmas |