As I have said before, there is no such plant as "Cereus peruvianus".
The plant passing under that name in the horticultural trade is something
else.

Again, quite correct. Again, irrelevant.

+ + +
Let's try and keep some perspective here. If the plant known in
horticultural circles as "Cereus peruvianus" is something else entirely then
this is not irrelevant and at best the name should be used between quotes.

On the other hand if this name is well established in horticultural circles
it will be with us for some time to come and any headlong attack on it will
be pointless and fruitless. These things take time, and a consitent policy
of gentle discouragement is the way to go

PvR