An old plant...

An old plant with no name......

Hi maurillio,

Maybe haageana subsp. elegans?

Possible, but there are 2,3 and also 4 central spine.
Stimma is green...

I believe that it is one of the many forms of M. albilanata ssp. oaxacana. The flower looks right, whereas on M. haageana they tend to extend way beyond the tubercles, and also the stigma is greenish, which is also right for ssp., oaxacana. Spine counting isn't a reliable way of determining a species, as there is often a lot of variation, and the formal description would have been of just one or a few collections.

Now as to which form, I am not sure. The amount of wool varies such a lot, even within the same "old" named species, such as lanigera etc....

Grazie Delandmo and grazie Chris.
Ottime analisi.