Cactus Identification

[237SJ]

Does anyone know what the cactus is that is to the right in this picture please? http://cactiguide.com/cactus/?genus=Armatocereus&species=arduus

[Buenchico]

It looks like a (fairly young) Old Man Cactus (Cephalocereus Senilis) to me.

[237SJ]

I`m not sure as this is the Old Man Cactus and I don`t think it`s that http://cactiguide.com/cactus/?genus=Cephalocereus&species=senilis

[Buenchico]

The 'hairs' don't grow very much on an OMC when it's still fairly young. (They need to be several decades old to take on their full hairy appearance). The cactus in your picture has the distinct erect tubular appearance of an OMC, together with a thin covering of hair, so I still think that it's the most likely candidate.

Back in my teenage years I was a keen member of the East Anglian Cactus Society and I always aspired to own a large OMC but I could never afford to. (A fully grown specimen, at today's prices, would cost many thousands of pounds). However I saw many young plants and they looked very much like the cactus you've asked about. Further, I saw loads like that, clearly labelled 'Cephalocereus Senilis' in Madrid's Royal Botanic Garden last year.

However I could still be wrong!

[237SJ]

I just don`t know, Chris. I must admit I`m not a fan of cactii. I`m trying to identify the cactus as it`s one my Mum has on her windowsill. It is tall and the prickles are very fine. It is about 29" and two more have grown in the pot which are a bit shorter. Underneath the hairs, it`s smooth - there are no ridges. My mum has lymphodoema in her arm and must be very careful about any kind of injury and tonight she knocked the cactus. It fell and she caught it with her bad arm and got lots of prickles which can be bad in her case. I want to give the *** thing away on Freecycle which is why I`m trying to identify it.

[237SJ]

I think it might be Pilosocereus aureispinus but I`m not sure.

[jno]

not one of these, is it?

http://tinyurl.com/n4z3wvn

[EcclesCake]

Looks like a Cleistocactus Strausii to me.

[237SJ]

I don`t think so jno. Thanks for the link anyway. Eccles - I`ve looked at some pictures of the Cleistocactus but Mum`s one doesn`t have the ridges. The spines are not white either - they`re a short of yellowy colour. The trouble is, so many varieties look similar.