I decided to have one last look before completing and posting my entry for, and found another possibility: Christmas Bells. It's one of several names that Sandersonia's known by.
I am pretty sure that the Christmas Cactus that I previously had did NOT have prickles. And that is why I think the answer is Christmas Cacti as it is a play on words re prickles as cacti have prickles but Christmas Cacti do not.
I think.......