Never knew a succulent cactus - split rock can blossom. I found it with a blossom stem back a couple of months ago. Then, slowly, it opened up in mid-March just when self-quarantine order started. It was an amazing hours watching it open up and closing on time daily with the sun.
Other Cati family in bloosom this year - Christmas cactus has been blossoming quite regularly. I think it really likes its humid Aquarium home. It's out of the aquarium for these flowers to have enough room to expand.