Some years ago I got what has been identified for me as Disocactus x hybridus (or possibly ackermannii), and it keeps breaking - I don't have the heart to throw the pieces out, so now I have too many plants in various states of repair; hence I offer them for sale to anybody who can come and pick one...

Thank you! I looked in wikipedia, and apparently it is now called Disocactus. I mostly grow orchids, and I find you have to run to keep up with the name changes - is it the same with cacti?

I have over the years acquired a number of cacti, but I know very little about them, but I have always wanted to know what they are and how to treat them. This one I have never seen anywhere else - it seems to hide underground, like a potato, then sends out long, thin branches. It has never flowered...

Can anybody identify this one? I was given them several years ago, being told they are 'San Pedro Cacti', but they are far too spiy, compared to the pictures in wikipedia and elsewhere. They live outdoors all year in London, UK, under a plastic roof:

I inherited this one years ago, and being a cactus novice, I don't know what it is, although I see them in many places, but without flowers - can somebody tell me?