Any Ideas on this plant?

A member of the public brought this into the gardens during the week. I know what I think it might be but would like to hear suggestions.

Probably spinosissima, but I need a closer look

the plant is about 2ft across (70cm). This is a close up of the spines. There are between 4 -6 brown spines per tubercle. There are no radial spines and plenty of dried flowers all the why down the heads but no fruit or seed pods

Now I have more doubts about this plant, I am not so sure anymore that it is in fact spinosissima.
Have you seen it in flower yet?

No I havn't seen it in flower yet. It only came in last week. I to thought it could be spinosissima, possilbe subsp tepoxtlana grown in poor light. Its hard to tell without flowers. It might not be a mamm at all !

I was tempted to say it might be a form of polythele, because of the cylindric and pendulent form, and the lack of radials. I think its safe to say that polythele is the only species in both the Heterochlorae (and Rhodanthae) and the Polyacanthae that has no radial spines.
But then I looked at the close-up again, and are you sure, Mark, that it has no radials. On the head to the right of the close-up, near the apex, just below (well above actually since its upside down!) a brown dried flower, I'm sure I can see a number of very short white spines on a number of tubercles. Its a little difficult to see, but I think they look more distinct that I would expect from just wool, although they are very short.
If that's the case, then I'd like to know how many, as I also don't think it is spinossima, which has lots of radials, and I've never seen one with such short radials.

Well spotted Chris. I did not see any radials and I had the plant in front of me. I have taken off some of the spine cuslters and there are 11 radials. Fine, white and just a few mm's long.
Mark

Thanks for the confirmation, Mark. I am still pretty uncertain, and have a couple of thoughts...
maybe verticealba (or rhodantha ssp mccartenii), or a straight spined version of nunezii...
but none really fit those very short radial spines. I end up thinking its a very unusual form or a hybrid. What do others think?

Hello Mark and Chris,

I was also thinking it is a rhodantha form, who spent most of his life in a darker zone than in a greenhouse.

9-7-08. The plant has now come in to flower and it would appear that both Chris and Hugo are correct in that it seems to be M.rhodantha. I would go has far to say that it is subspecies aureicpes apart from the spination which calls for golden - yellow spines. These are a dark red - brown colour but given the variable factors in both spines and flowers of many species it's not that much of a problem.