Mammillaria duwei ?

Hi,
I have two Mammilaria duwei that I bought from a freind who obtained seed somewhere in Europe (he couldnt remember the exact supplier), they seem to have less pubescent radial spines and clump very freely. Also the overall form seems finer than my other duwei's I have which definitely seem correct (big taproot, pubescent radial and centrals, one though has only radials, and a big tap root). Flowers are correct. The other thing with these two clumping ones is that they form what looks to be seed pods which explode into offsets instead. As I read that duwei comes from a population of nana that is quite restricted I wouldnt expect too much variability. Any thoughts as to whether these may be hybrid, a form , mutation and the seed pod/offset thing ?

That looks more like pennispinosa v nazasensis

It certainly looks like a hybrid.
About ten years ago, I saw a M. duwei in Walter Hellinx's collection, which carried my field number WTH 460. This certainly was a hybrid. Walter told me that it was grown from seeds which I had given to the German Mammillaria Society and which had appeared in their seed list. In those old days, I did not completely exclude bumble bees from entering my greenhouse (nowadays I do) and I assume that it was not only I, but also bumble bees who had pollinated my duweis (which I had grown from habitat seed, i.e. OK).
To me, it was clear that M. duwei can be hybridized. I threw away my own (hybrid) seedlings, except for those seedlings which looked like the real duwei (yet, I don't use these plants for pollinations). Among those duwei seedlings there was even one which produced reddish flowers. I would have liked to see that one grow up, but sadly it died soon after the first flowering.

Another mammillaria where I have noticed hybridization in my collection is M. swinglei WTH 681 (grown from habitat seed). The plants which I grew from their seeds sometimes had reddish flowers, which was not what it should be. I wrote to the owner of the German seed list that he should throw those seeds away, which he did only a year later (current WTH 681 seeds in the AfM seed list are OK, though).

Nowadays, the doors and self-opening windows in my greenhouses are covered with a net, such that bees cannot enter anymore.

So, to all who pollinate their plants: exclude bees!

Regards,

Wolter.