Just wondering how many Mamms have soft fan shaped, plumosa-like spination? I know of plumosa, carmenae, theresae, hernandezii, luethyi, saboae (kind of like it... but not very...). I have one whose soft fan shaped spines are on long tubercles. I'm leaning towards carmenae because the new growth is emerging yellow, but the plant is new and was poorly grown in the early stages (so radials in poor condition... lots of overhead watering here in winter etc). I have carmenae as well for comparison and decided there was enough of a difference to be inconclusive. Maybe it's a carmenae hybrid???

New growth:



Old damaged growth:

There are a number of hybrids between M. carmenae and M. laui, which exhibit variable spination. Is it an offsetting plant, and has it flowered yet?
There are also plumose forms of M. schiedeana, which might have the longer tubercles, but I'd like to see the whole plant as well as just the spines.

Thanks Chris. Can't tell you much about it yet as I've had it under a week. At the moment it's a small solitary plant approx 4cm high and wide. I imagine it will begin to offset with more age. The tubercles are approx 10-13mm long. I'll try for a whole plant photo over the next day or so.

maybe not that long.. 7-10mm looks more realistic on 2nd thoughts.