Little burnt-looking bumps have been popping up on this cactus and I'm not too sure what to do about it. Can you help me figure it out?
I believe that this is a cactus form the Genus Mammillaria. Not sure of the specific species. This appears to have been grown either low light or too much fertilizer (or both) for quite some time.
The confusing part is that it is nice and green, plants grown in too little light are generally lighter green. It is definitely distorted though. The spines appear to be very weak and thin and are missing in several places (not well attached, perhaps?)
As far as the brown dots, let us know if you can get one off and what is inside. I suspect it is an pest of some sort, but I've never seen anything like that.