Mammillaria help needed please

[gillinger]

Could these two be variations of the same? I'm thinking M. tetrancistra.

[zpeckler]

Just playing the odds, a Mam with reddish fishhook central spines and light radials is probably gonna be bombycinia. I love native CA cacti, and because of their reputed difficulty in cultivation I've never seen either tetrancistra or dioica for sale as mature plants--and believe me, I've looked! Availability might be different in the UK, of course. If it is a tetrancistra, then lucky you! I'll admit that in habitat in the Mojave I have a hard time telling it apart from dioica unless it's flowering.

If you do have an interest in growing either of those species I've found seeds at Mesa Garden and Phoenix Desert Seeds. I sowed 50 of both those species this year and almost all the dioica germinated and almost none of the tetrancistra did!

[anttisepp]

I'd think about moelleriana and magnifica.

[MikeInOz]

I'd think about moelleriana and magnifica.

Yes I think both are magnifica.

[greenknight]

I'd think about moelleriana and magnifica.

Yes I think both are magnifica.

I agree - though the spine color on the first is unusually dark for magnifica, spine color varies, and everything else about it fits that taxon.

[gillinger]

Thanks, everyone. I'll follow those suggestions up. I already have a bobycina but these two don't look the same as it,, although with wide variations on most species I guess it's not impossible.

[DaveW]

Mammillaria bombycina gets its name after Bombyx mori the silkworms fluffy cocoon since it has similar silky wool in its areoles. Therefore far more woolly than your plant gillinger.

https://www.llifle.com/Encyclopedia/CAC ... _bombycina

Mammillaria perezdelarosae is a closely related species to Mammillaria bombycina and again hard to mistake for any other Mammillaria.

https://www.llifle.com/Encyclopedia/CAC ... zdelarosae

The subspecies Mammillaria perezdelarosae ssp. andersonii mainly differs in having straight not hooked central spines.

https://www.llifle.com/Encyclopedia/CAC ... ammillaria.

Once you have seen them the Mammillaria bombycina group are hard to mix up with the other Mammillaria species since they have obvious copious wool or hairy radial spines in the areoles.

Mammillaria tetrancistra is difficult to cultivate, but Mammillaria dioica is no problem usually. It gets its name from being dioecious or having male and female flowers. However that varies as the quote below says for M. dioica:-

"The flowers usually are imperfectly unisexual, occurring on functionally dioecious plant, but some plants have flowers that are strictly female, with no stamens."

https://www.thespruce.com/difference-be ... ts-2131039

[MikeInOz]

Mammillaria tetrancistra is difficult to cultivate,

Hi Dave. I have found it difficult as well. I looked up the rainfall pattern of it's habitat and discovered it was opposite to usual Mam habitats. ie; ''wet'' winter, dry summer. (Mediterranean in other words)
https://en.climate-data.org/north-ameri ... side-1425/
I have one left from a batch and plan to keep it drier in summer and give a little water in the cooler months and see if that helps. This habitat rainfall pattern is not mentioned in any of the books I have. It could very well be that watering this species when the weather is hot and the plant is dormant will kill it? I have certainly killed my fair share when I treated them like frailiana etc. Maybe grow them with your Conophytums.

[zpeckler]

Mammillaria tetrancistra is difficult to cultivate,

I looked up the rainfall pattern of it's habitat and discovered it was opposite to usual Mam habitats. ie; ''wet'' winter, dry summer. (Mediterranean in other words)

I have one left from a batch and plan to keep it drier in summer and give a little water in the cooler months and see if that helps. This habitat rainfall pattern is not mentioned in any of the books I have. It could very well be that watering this species when the weather is hot and the plant is dormant will kill it? I have certainly killed my fair share when I treated them like frailiana etc. Maybe grow them with your Conophytums.

Oh yeah, the Mojave and Colorado Deserts get almost exclusively winter rainfall. This makes the species that grow there different from what's adapted for the Sonoran Desert and the Colorado Plateau, which gets summer rain.

I'd be interested in seeing how your winter watering strategy goes. It's what I'm planning on doing with my M. tetrancistra, M. dioica, and E. polycephalus seedings I've got going on right now. They're only 2 months old so they've got a bit to go.

[DaveW]

Maybe an occasional mist spray in winter would be safer than a heavy watering?

[anttisepp]

Here's a photo from https://www.kakteen.cz/en/mamillaria-magnifica/ : spines of different colour:
https://cdn.myshoptet.com/usr/www.kakte ... g?6348156d

[gillinger]

Good luck if you ever wanted to separate those or repot! I repotted both mine and it was the most difficult job I've done with cacti. Those spines attach themselves to anything within a 3m radius!