I was contacted by phone by someone who was asking for advice on a plant. He believes it to be a Trichocereus, and it has developed some unpleasant black blodges. There appear to be other marks as well.
I asked him to send me some photos which I am posting below. The plant is normally grown on a windowsill but was placed outside in full sun. It has also been fertilised with some sort of generic plant fertiliser, it has not been sprayed. Before I saw the pictures I suggested that it was a very severe case of scorch caused by the sudden exposure to bright sunlight.
I would be very grateful for the opinion of other people who are more knowledgeable than I am, which I will pass on to him.
Bridgesii are prone to this in my experience , I think it is more the change in humidity rather than scorch as I have had it happen to one placed in shade but a much more humid environment .As long as the growing tip is undamaged the plant will recover though those areas will cork and maybe deflate.
