Mammillaria uberiformis

Mammillaria uberiformis is described without central spine.
In my young seedlings there is often a central spine short and stout.
At first i thought an hybrid, but then reading tha "journal of the mammillaria society" - vol.12 number 2 - in "review of Mammillaria names in current usage (part 24) by D.R. Hunt:
M. uberiformis Zucc. in Pfeiff. , Enum. Cact. , 23.137 (type locality: Pachuca, Hidalgo) should almost certainly be ragarded as a synonym, thought upheld as a species by most authors.
It is supposed to be differentiated by shorter tubercles and fewer (darker) spines, but these characters are unrealiable since they seem to vary indipendently.
Living plants in Kew collection supplied from two sources as uberiformis have uniformly 8/10 radials and 1 central spine, but tubercles less than 3cm long.
A wild-collected specimen (from Hidalgo): between Ixmiquilpan and Tasquillo, Buchenau) has 6 radials and tubercles about 2.5cm long.
Another wild-collected plant, labelled M. longimamma has tubercles of about this lenght too, but average 9 radials....... segue.

Then i cannot find other comments about the presence of this central spine cited by hunt exept in my plants.



Mammillaria uberiformis REP 1000

In Reppenhagen's book, volume 1, page 54, he describes M. uberiformis as sometimes having a central spine. I understand that the main characteristic that distinguishes it from M. longimamma is the root. It was first described from Pachuca, Hidalgo, where M. longimamma grows as well. I find it difficult to believe that it is anything other than a variation of M. longimamma, especially as no type specimen was conserved. I have seen M. longimamma in a number of locations in Hidalgo, including Pachuca, and Queretaro, and the spination does vary, as does the tubercle length. I didn't dig up any so cannot comment on the roots. I have a plant Rep620 in my collection, and I don't remember anything noteworthy about the roots. I shall have to check when I next repot.

I've been checking some of my photos of M. longimamma plants in habitat, and I can see that in some locations, there are plants that have a single central spines on some areoles, but none on others. In the same locations, there are plants that have a single central spine on all areoles.

My REp 620, which apparently comes from even further west, near Villa Victoria, Guanajuato, doe snot have a central spine.

Here's a plant that I saw near Bellavista del Rio in QWueretaro, which from a spine point of view, would appear to be f. uberiformis.



and a crop that shows the spines pretty well.



M. longimamma is a very widespread species, and some variation is to be expected. The fact that M. uberiformis is reported from Hidalgo, Queretaro, and Guanajuato, just like M. lomgimamma, suggests to me that M. longimamma is very variable, and that is all we are seeing. The use of M. uberiformis as a name which has significance is wrong.

molto completo e dettagliato.
grazie molte chris.