With good help from the community it seems that I've got identified all my Mammillaria sp.s, except for one. Can you please identify this difficult one ?

Could you try a different exposure?

Thanks for the reply. I believe the photos are as good as I can make them

Golgatha said: Thanks for the reply. I believe the photos are as good as I can make them

White/gray background, less sun.

Does it have yellow flowers?

Unfortunately it hasn't bloomed in my ownership.

Too cold outside for cacti (and for me), so here are two indoor shots. I hope they help !

Going with prinlwi

skopjecollection said: Going with prinlwi

Did you mean pringlei? I'm growing that one. Here's a couple of photos of mine. It's grown larger than the side view photo, but has basically retained the same form.

needrain said: Did you mean pringlei? I'm growing that one. Here's a couple of photos of mine. It's grown larger than the side view photo, but has basically retained the same form.

Wow I sure messed that one up badly....
But yes. Pringlei...in less than ideal conditions...

Thanks ! I hope you're right, because I'm preparing a number of plant name labels and I'll give it the Mammillaria pringlei name.

I dip the wooden sticks in ship lacquer, place a computer written name in the lacquer, allow to dry and dip the stick once again in the lacquer and allow to dry so the surface is protected. Se the example. Maybe you have a better suggestion ?

Pretty sure Id just dip it in oil. Lacquer seems to be caustic to me.
On the name. Not 100% certain, but it oddly reminds me of my old rhodantha that I donated, if a tad spinier and of course , yellow.

Actually, Wikipedia lists M. pringlei as a synonym for M. rhodantha and as a subspecies for rhodantha. For me, they do grow similar but due to the spine color don't really look the same. I read, and Google Images have examples, that the pringlei version has a tendency to dichotomize (a trait mine is not showing yet). Some photos on Agaveville also show it as a subspecies with some showing dichotomy
https://www.agaveville.org/vie...
@mcvansoest Thijs probably has knowledge more definitive that I do on this.

For comparison, here's a photo of my M. Rhodantha. For me, this one is a generous bloomer over a long period. The visual effect of this one is very red whereas the pringlei is very yellow.


Edit - another webpage you might check out is Llifle http://www.llifle.com/Encyclop...

The reason I asked about yellow flowers because it makes me think of M. marksiana.

mcvansoest said: The reason I asked about yellow flowers because it makes me think of M. marksiana.

I thought of it but those are supposed to be short and wide.
It does remind me of another , similar to marksiana which I had. But also short and wide.

Nivosa, thats the one

I tried Google picture search and it suggested (among others) M. spinossisima. What do you say to that ?

Golgatha said: I tried Google picture search and it suggested (among others) M. spinossisima. What do you say to that ?

Strong no. I had both varities

Agree with Stefan not spinosissima.