Mammillaria Painterii?

[Hero878]

Not sure if this is Mammillaria Painterii? It looks too dark. I saw it at a cactus nursery but forgot the name of it and my photo doesn't capture the name tag.



Thanks

[Glorioustache]

Looks like a Mammillaria luethyi I would say

[Hero878]

Thank you that's certainly the one! I'll be adding it to my collection next year when the grower has more must be one of the rarer most sought after Mammilarias out there. The colour its amazing.

[Glorioustache]

You're welcome! And yes it is definitely a rare one and very sought-after as you said, beautiful species. Great addition to your collection for sure. I have wanted one for a long time but I can only find it grafted over here and I don't really like grafted cacti. Hopefully I'll find one on its own roots one day

[Hero878]

Awesome! The ones for sale at my local nursery are also grafted but since they grow much quicker grafted I suppose I can eventually remove an offset and root it on its own.
I am recently grown to favour grafting because with rarer species I think I won't have to worry too much as it'll be more hardy and as a bonus faster growing
My local nursery uses short stock too so after a few repots the graft is hidden away.

[DaveW]

I have never yet been able to root an offset off a graft of either Aztekium ritteri or Mammillaria luethyi. I understand they are not too difficult on their own roots if you can get one grown from seed, but Aztekium is mind numbingly slow from seed. However as M. luethyi are cryptocarpic with the seed buried in the body they are not a commercial proposition for seedsmen to sell seed, therefore usually mostly propagated by grafting.

See how the seed is retained in the body at the bottom of the link. I don't know if they are self fertile either? If not you would need two clones to produce seed and most grafts could be from a single clone. The seed also seems to germinate better if aged. Some claim most seeds in the wild are retained in the body and only germinate in the remains of the mother plant when it dies. Again how true that is I do not know since I have never been able to get M. luethyi seeds?

This quote from the link below:-

"Cryptocarpic fruit: Mammillaria luethyi is one of the few species of cactus with cryptocarpic fruits. That is, the fruit and seeds are produced and retained inside the stem of the plant. After the flower is finished and dropped off, the stem closes over the fruit and the fruit/seed gradually ripens within. The following years the fruit may remain within the body at the axil, or may protrude a bit. A thin membrane will be above the part where ripe seed can emerge. As the plant swells with the new growing season, the membrane fractures, and some seed from the past years can little by little drop down and germinate in the close proximity, forming small colonies.
But usually the seeds remain within the plant body for several years or for the whole life cycle of the plant, and frequently they will be released only at the death of the plant after the disintegration of the old stem."

http://llifle.com/Encyclopedia/CACTI/Fa ... ia_luethyi

I have have lost a couple of grafted plants when the scion dehydrated and parted from the stock in winter and then completely dried up even though the stock was still healthy. Obviously being tuberous rooted the tuberous root would keep them going over winter but is not there on a grafted plant, This may be the result of differential shrinkage or contraction of scion and stock in winter since the link says:-

"Seasonal growth and contraction: In the wild these plants contract considerably during the dry season, sometimes pulling down completely under the soil level, and frequently the flowers push up through the dirt from the underground cactus body. In fact, even though these plants show a good amount of new growth each year (at least 1 or 2 cm), they hardly get any larger, and their dimensions remain unvaried year after year, as the individual stems tend to contract at the base. The new growth produced during the vegetative season compacts considerably and retracts sometime, pulling the plant down completely under the soil in the hottest months of summer and coldest months of winter.
It should be noted that "when specimens are in this withdrawn state, it becomes almost impossible to find them in their natural state, even though their exact locality is known"

[Hero878]

That is very interesting. Seems this species just wants to be difficult.
John at Croston Cactus said he'll have some next season so I will ask him how to grow it so that it doesn't die off even when grafted.
I wonder if he harvests the seeds by cutting into the stem...though he probably just detached the offsets.

[greenknight]

They can propagate these many times faster by grafting - don't need offsets, just tubercles cut from a mother plant. Here's a video that shows it: https://www.youtube.com/watch?v=HA3ZIjHGKZ0

In that video, they're grafting many tubercles onto an Opuntia pad, which allows doing many of them quickly and cheaply, but those that succeed could be later cut off and re-grafted onto individual rootstocks.

[Hero878]

They can propagate these many times faster by grafting - don't need offsets, just tubercles cut from a mother plant. Here's a video that shows it: https://www.youtube.com/watch?v=HA3ZIjHGKZ0

In that video, they're grafting many tubercles onto an Opuntia pad, which allows doing many of them quickly and cheaply, but those that succeed could be later cut off and re-grafted onto individual rootstocks.

Wow I had no idea all you needed was a tubercle thanks . I'll definitely give this a try looking forward to seeing what results I get

[DaveW]

Some very large tubercles like Dolichothele's after callousing you can root down normally, just as with offsets. However most smaller ones need to be grafted straight away or otherwise they dehydrate and shrivel up before they can root. However when the graft produces a larger plant you can de-graft and root that down. Therefore to save the species it can often be done through tubercle grafting.