Lophocereus schotti monstrosus - Totem pole cactus|
The cactus family is a very young family of plants, and so have a lot of variation within a species. The normal form of Lophocereus schotti (one i or two?) is a standard column cactus. This form is commonly called 'monstrous', or 'monstrosus', or probably other colorful (or is it colourful?) descriptors.
Anyway, this form of Lophocereus schotti is kind of delicate. Well drained soil, full sun...I give it less water than other cactus, because it tends to develop black spot fungus, a common catch-all term for any number of fungi (or is it funguses...fungii...fungiforms...) that show up on leaves and stems of many plants as black spots. It's very hard to cure black spot on Lophocereus schotti; even amputation usually won't save them. Prevention is the best cure, and prevention means dryness, in the air and soil both.
This picture makes it look like I'm strangling the poor thing, but it's actually a loose tie of cotton string to a fence because it had only recently been planted.