"Mary Fisher" wrote
01 taken at beginning of June when in bud, others taken a few days ago.

Sorry, I did reduce the size, honestly. Not enough, obviously :-(

Mary, that is a perfect picture of a monstrous growth, it's something that
happens to plants when the growing tip is damaged and it flattens out into a
line instead of a point. You often see Cacti grown like that deliberately,
making a sort of crest.
It may be a chemical you have used or some other reason so I would suggest
you repot when it's dormant, be careful what you use on it next season, and
see what happens next year.

--
Regards
Bob Hobden