Four white Mamms for Identification

Hi all,

I acquired some Mamms recently which had no labels, and while I have some ideas as to what they might be, I would like other people's views to help me come to a conclusion.

Mamm 1 - plant:


Mamm 1 - crop:


Mamm 2 - plant:


Mamm 2 - crop:


Mamm 3 - plant:


Mamm 3 - crop:


Mamm 4 - plant:


Mamm 4 - crop:

#1 could be Mammillaria dealbata








#2 could be Mammillaria albilanata ssp oaxacana











#3 Mammillaria albilanata

# 4 Mammillaria haageana, maybe ssp. elegans

Thank you, Maurizio. Your suggestions are very helpful. I'll add a few of my own thoughts tomorrow.

I've done some more book searching, and I think you are right about #1, and also #2. This last one looks very much like the plant illustrated in Pilbeam as Rep 844.
I did wonder if #3 was albilanata, so I can accept that happily.
But I am by no means certain that #4 is M. haageana (elegans). This is described (like haageana, the type) as having just 2 central spines, and while I know this can be a variable feature, plant #4 has at least 4 central spines, white, tipped brown, and I wonder if that isn't yet another form of M. albilanata ssp. oaxacana, maybe M. ignota.
It doesn't look as the first three have flowered for their previous owner, although they are mature plants, so hopefully a repot and some fertiliser will bring them on next Spring, then maybe we can see if the flowers confirms our thoughts.

Hi Chris,
I would personally call the first three supertexta and the 4th as you suggested albilanata sub.oaxacana, ignota as you say or maybe lanigera.

Hi Del,
I had wondered about supertexta, of course, but had discounted it for plants 1 and 3 because of the 4 central spines. The description of M. supertexta calls for just 2 central spines, but Pilbeam says that it should also include M. lanata, which has no central spines. For plant #2, spine counts do match M. supertexta, as do the woolly axils, but it also is well within the description of albilanata oaxacana.
Of course these species are quite closely related anyway, and without knowing where they come from you could just toss a coin! I plumped for the latter mainly because the plant is an old one and is more globular than cylindrical as supertexta tends to get.

Maybe my conditions are favourable, but plant #2 has just put out a flower, clear red-purple, like a good red wine. It has also pushed out a seed pod on the opposite side of the plant. I could swear they weren't there a couple of weeks ago when I took the earlier photos. The fruit is short, only just beyond the spines, and has a substantial flower remnant. I have checked the reference books again, and this doesn't fit M. albilanata ssp oaxacana, whose fruit is said to be 10-25mm long. I am moving towards M supertexta for this one.

Here are the images: