This is a picture of Cleistocactus samaipatanus in flower. It's one of my favourites, the first 2 photos were last night the third this morning. I had to put a picture up after mentioning this plant in 2 previous threads. First was this one with a wayward snail:
At the time of my 1st post I had it named as Borzicactus samaipatanus. Here is why:
It also appeared in my 'Too many names..' where I mentioned it can also be Bolivicereus croceus, Bolivicereus rufus, Bolivicereus brevicaulis, Borzicactus roseiflorus, Akersia roseiflora, Borzicactus samaipatanus, Bolivicereus samaipatanus.
After doing a few searches I found that Cleistocactus is the most commonly used name.