This is what we always called a Christmas Cactus. Learn How to Get Your Christmas Cactus to BloomHere is a picture of what we have. Not sure that it is the same as the OP's. Wife said we got it back in the 70's. Ours has small, prickly spikes along the green leaves/stems. Does not flower very often, but when it does it an orange isg/red flower. No picture of the flower though. Jon
The OP's plant is also known as a Clivia. It's supposed to be a good plant to keep inside in winter months, as it helps to clean the air.