I'm confused...

I sowed a lot of Mammillaria species back in 2011, and now that they've started to flower I'm a little confused.

First off, Mammillaria gasseriana "Ojo de Agua", seed from Piltz (#1723)



It's not quite the description, but still I can accept it.

Next I have Mammillaria chica "Viesca, Cohauila", seed from Aymeric de Barmon (#855). It seems that Mammillaria chica is now correctly refered to as Mammillaria gasseriana, but the two plants look really different.



I am careful at the time of sowing, and being that the seeds come from different sellers as well the chance of me having confused packets is small. What do you think?

I think that what you are seeing was caused by the lack of understanding of the hooked spined plants of the Lasiacanthae series, in particular M. stelal-de-tacubaya and M. gasseriana (chica, viescensis etc).

It is difficult to be certain without more detailed field location data, but I would suggest that your first plant is actually M. stella-de-tacubaya, and the Ojo de Agua mentioned is probably the same as Rog 004 and ML607.

As far as your second plant is concerned, I am slightly surprised that it has no hooked central spine, which in this species (gasseriana) is usually thinner and longer and lighter brown than that of M. stella-de-tacubaya. However the presence of central spines does seem to be a variable feature in a number of these species.

Thank you, Chris. The first plant is indeed a good match to M. stella-de-tacubaya. Maybe the other will grow into something more identifiable.

I think that both plants conform to what grows at their natural locations.
Your M. gasseriana from Ojo de Agua is indeed M. stella-de-tacubaya. Its location is about 20 km west of Sombrerete, near the villages of Villa Insurgentes and Ojo de Agua. I do not have the Rogozinski number on hand, but Rogo has long maintained that plants from this region are M. gasseriana (in several articles in the German Mammillaria journal). I do not think that he is still hanging on to that opinion.
In the seed list of Steven Brack you will also find M. gasserianas which are actually M. stella-de-tacubayas. All in all, there has been much discussion and confusion about what the real gasseriana and the real stella-de-tacubaya are.
Whatever name you attach to it, your plant conforms to plants from the Ojo de Agua location. My seedling plants very rarely have a hooked central spine, but the mature plants do not form that central spine anymore, at least not in my greenhouse (my seedling plants were grown from seeds of plants which did not have central spines; it could be that my location is slightly different than the Rogozinski location, but not more than a few km from it).

Your M. chica corresponds to the description of Reppenhagen, there is only very rarely a central spine. In my opinion, this is a form of M. lasiacantha which sometimes forms hooked or straight centrals. Those centrals are especially present in young plants. East of Viesca I found similar plants which had an occasional straight or curved central spine. West of Viesca, at what is supposed to be the type location for M. chica, I found plants with hooked to slightly curved centrals. The attached photos show some of these latter plants.
North of Viesca you will find the 'real' M. gasseriana (viescensis is a form of it) which almost always has hooked central spines, but as Chris already said, these centrals are fairly thin.

Of course, there is a chance that hybridization has occurred in the seed seller's collection, but if the seeds all lead to uniform plants then the seed was probably of non-hybridized origin.

Wolter ten Hoeve.

Thank you, Wolter. I envy your knowledge of the distribution and habitats of these plants!

Well, after more than 10 trips through Mexico, searching for cacti (especially Mammillarias), I admit that I have gathered a little knowledge. However, a lot of credit goes to people like Michel Lacoste, Helmut Rogozinski, Thomas Linzen and others who provided me with valuable information, based on their field knowledge (and much of their knwoledge was gained from people before them). Without the information of others I would not have found plants like M. hernandezii, M. saboae, M. perezdelarosae andersoniana. For instance, M. saboae I only found because I had the exact GPS from someone else, but even then I had to get on my knees to find the plants, so well hidden they were. The person who first discovered this species probably found it because it was in flower.

Wolter ten Hoeve

I'll try to save enough to tag along one of these days.