Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

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apoplast
Posts: 28
Joined: Sat Jun 24, 2017 12:58 am
Location: Minnesota, USA - Perfect for cactus, right?!

Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by apoplast »

Hello everyone - So, I'm looking for advice from experienced growers with the two species above. I suspect it will take me some time to find a source for each, especially because I want to grow them on their own roots. I figure it gives me time to make sure I do my research on them both first. I guess I should let you all know what I am aware of first.

For Mammillaria luethyi:
As a species in section Longiflorae, I expect this species to be have a thick roostock and probably be a bit rot prone than other Mammillaria species. Previously I've grown M. saboae with a good deal of success. There I used an all mineral mix that was coarser than I would for other small cacti. The elevation and habitat description make me think that if anything, M. luethyi will be quite a bit more rot prone and need more heat than M. saboae. Other than that, I'm not sure what I would need to do differently.

For Astrophytum caput-medusae:
Right off, I'll admit I've never grown an Astrophytum before, and my understanding is this one is more difficult. By the range and site description, my suspicions are that this species is native to finer grained soils. But that it still dries between rain events and is very warm in the summer rainy season, with a cooler but very dry winter. I'm thinking a faster draining mix than found in the native conditions will be needed here, but I'm unsure if it will react poorly to a coarser mix. I suspect limestone or small amounts of gypsum in the mix may help, but that's a total guess.

If anyone has grown these species successfully on their own roots, I would love to hear your advice. Thanks so much for reading this!
"If you are not killing plants, you are not really stretching yourself as a gardener."
-- J.C. Raulston, horticulturist, founder of the J.C. Raulston Arboretum in Raleigh, N.C.
DaveW
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Location: Nottingham, England/UK

Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by DaveW »

Only grown them on grafts since they are often mass propagated this way. You may be able to find both as seed, but if I remember correctly luethyi is one of those species that retains the seed within the body, therefore difficult to extract and so more expensive, hence most plants available are grafted clones since they have been produced vegetatively. I gather luethyi is not too difficult on it's own tuberous roots but seems hard to de-graft and re-root since it mostly seems to shrivel before rooting. It also has a nasty habit with me of drying up on the graft in winter, therefore some claim you have to give a little water through the winter rather than letting the stock go totally dormant. No doubt this does not happen on its own roots.

http://www.cactus-art.biz/schede/MAMMIL ... uethyi.htm

Astrophytum's are easy enough to grow, apart from A. asterias which seems a bit more tender in winter. A. caput-medusa is a bit more difficult on it's own roots, but see:-

http://www.cactus-art.biz/schede/ASTROP ... edusae.htm

The soils plants grow in habitat in often have little relevance to pot culture, since a small quantity of soil in a pot behaves differently to open ground. Basically you want something that drains fairly quickly and does not stay wet too long, so what mix you use often depends on your climate. In cold wet ones very free draining mixes are needed to dry very quickly, whereas in very hot climates mixes that dry out a little slower and may hold water a bit longer may be more desirable.

I don't know what country you are in, but presume the USA? We can find both plants within the EU and import without CITES problems and of course seed can be imported from anywhere in the world plus most dealers use Pay Pal these days to make changing currency easier.

http://www.gerardo.cz/en/181-astrophytum

Mammillaria luethyi seed, because it is retained within the body, is harder to find than even the new M. bertholdii, but that at present still sells at a premium until it becomes more common. Hence M. luethyi is still mainly found grafted.
apoplast
Posts: 28
Joined: Sat Jun 24, 2017 12:58 am
Location: Minnesota, USA - Perfect for cactus, right?!

Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by apoplast »

Hi Dave - Thanks for much for the detailed reply! Yes, I am in the States. Not immediately obvious to me yet where I edit that so I can add that to my profile.

You folks in Europe have such wonderful selections of plants. It's true in carnivores as well. There, the Czechs are preeminent at prolifically propagating perfectly produced plants. Here it seems like we have a bit fewer options, or we need to import from Europe. Maybe it's the same way with cacti as well?

Your remember correctly that M. luethyi has cryptocarpic fruits making them a challenge to harvest. I suspected this was a cause behind the scarcity of seeds. But you mention that you have had difficulty getting a grafted plant through the winter. Did it bloom first? If so, have you ever dissected the remains to look for seed? I'm curious because if I could get different clones on graft and pollinate them, even if they didn't make it through the winter, perhaps I could salvage seed.

Spoke with someone today in the States propagating A. caput-medusae from seed, and growing it on its own roots, so hopefully in not too long that species will be available here.

Thanks too for your thoughts on soil texture. I guess I have mostly run into this with sand particle size, and more often with arenophilic species from dunes. Most are okay, but there are a few that really want to be in sand, and of those some will sulk if you get the wrong particle size.

Thanks again for the input. Further searches a head for information, and plants/seeds!
"If you are not killing plants, you are not really stretching yourself as a gardener."
-- J.C. Raulston, horticulturist, founder of the J.C. Raulston Arboretum in Raleigh, N.C.
DaveW
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Location: Nottingham, England/UK

Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by DaveW »

I think the problem with most grafted M. luethyi is that they are mostly clones from the same plant, just as the red chlorophyll deficient grafted Gymno's are. Therefore unless the plant itself is self fertile you need another clone to cross pollinate for seeds. I have flowered it but never found seed hidden in the body of the dead scion. Probably there are different clones, but unfortunately nobody has bothered to label the different grafted clones, therefore obtaining another clone will be a bit hit and miss.

It is an interesting thought being cryptocarpic if seed is ever naturally shed during the plants lifetime, or does it need death of the plant and it disintegrating to sow itself in the wild? I have heard it said fresh seed does not germinate too well, so maybe it naturally needs aging if it has to wait normally for the plant to die?

See:-

http://forum.bcss.org.uk/viewtopic.php?f=1&t=152640
apoplast
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Joined: Sat Jun 24, 2017 12:58 am
Location: Minnesota, USA - Perfect for cactus, right?!

Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by apoplast »

Hi Dave - Thanks once again for your reply! Yes, I do wonder about the genetic diversity of the many grafted specimens. Seems lime one person in the link was able to cross two grafted plants and get germination, but I'm with you that it might not be all that common.

Cryptocarpic fruits in these cacti are an interesting thing indeed. Outside of the issues for horticulturists, their ecology intrigues me. In many ways they remind of serotinous pine cones or the serotinous follicles on some of the Proteaceae in Australia. The idea of holding your seed in seem counter intuitive. Certainly the elevations where M. theresae and M. saboae are found naturally found would be fire prone. If they are holding their seed until their are top killed by fire, which would expose more rock after rains, it could advantage them. Not sure if their tuberous roots would persist or not though. The adaption of cryptocarpic fruits to fire would perhaps then be relictual in M. luethyi at lower drier elevations. All conjecture. But fun to think about.

Does anyone know if there have been studies of fire ecology in the Longiflorae series of Mammillaria? I'm guessing no given that even Bergerocactus, which is native to quite populated and studied environments, has been little studied in this regard. Plus, there would need to be a decent molecular phylogeny for the section, which seems lacking in most cacti currently. Oh well.

For now, it looks like I am going to have to intensify my search for M. luethyi seeds, as storage may only increase their germination. If anyone knows of a good, curent source or is willing to sell me some, please PM me. Thanks!
"If you are not killing plants, you are not really stretching yourself as a gardener."
-- J.C. Raulston, horticulturist, founder of the J.C. Raulston Arboretum in Raleigh, N.C.
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Aiko
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Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by Aiko »

apoplast wrote:For now, it looks like I am going to have to intensify my search for M. luethyi seeds, as storage may only increase their germination. If anyone knows of a good, curent source or is willing to sell me some, please PM me. Thanks!
Go to http://kaktusynechvil.wz.cz/offer.html next September or October, when the seed list gets updated again. Unlikely M. luethyi seeds are still available now.

Be quick when the list gets updated, or you will be too late to get any at all.
apoplast
Posts: 28
Joined: Sat Jun 24, 2017 12:58 am
Location: Minnesota, USA - Perfect for cactus, right?!

Re: Seeking tips: Mammillaria luethyi & Astrophytum caput-medusae

Post by apoplast »

Many thanks Aiko! With luck I'll get a few to try.
"If you are not killing plants, you are not really stretching yourself as a gardener."
-- J.C. Raulston, horticulturist, founder of the J.C. Raulston Arboretum in Raleigh, N.C.
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