August 2017 Aztekium ritteri

[Steve Johnson]

Not just rare, but the rarest of the rare -- and I was lucky enough to find one on its own roots through eBay in January. A. ritteri is notorious for being the slowest-growing species in the cactus family, so I really didn't expect to have it established well enough for flowering yet. This is pretty special, and we'll have a look at the ritteri's first flower under my care...

The plant's growth point already showing signs of activity in mid-March, then a tiny bud emerging from its wooly top on August 1:



From bud to bloom on the 2nd and 3rd:



View from above:



Yep, that's a bud hiding under the flower. The bud-to-bloom photos were taken at around 9:45 a.m., and it's interesting to note that the flower was already open at 8. Such being the case, the ritteri is the only early-morning bloomer I have in my collection.

If y'all wouldn't mind a bit of shameless self-promotion -- I'll post more photos of the ritteri over at my Member Topics thread. We have plenty of summer left, and I think you might enjoy following this lovely little gem's progress before the growing season comes to an end.

[DaveW]

Nice plant Steve, that is in fact a pretty mature plant on it's own roots since they are naturally small growing plants. Look forward to seeing more pictures in due course.

The New Cactus Lexicon gives the normal fully grown body size up to 5cm (= 2 inches) diameter. I have seen much larger grafted ones in shows but they are not typical for own roots size. Trouble is people expect all cacti to be big plants when some like Aztekium ritteri and Blosfeldia's are just little gems that never really get large if grown naturally on their own roots, seldom getting more than 2.5cm (= 1 inch) diameter.

I used to have Aztekium ritteri on it's own roots for years but lost it in a bad winter. It came as a rooted offset from a friends plant that he grew in the 1960's when they were even less common in the UK as cultivated plants since collected plants could be imported pre CITES, even if still expensive. Therefore being slow from seed few usually bothered setting seed. Seed anyway was hard to get and expensive at the time and sold at so much per seed, therefore my friend who could not afford a collected plant on his wages actually bought just one seed from a seed merchant and germinated and raised it. He told me it did not come in a seed envelope, but as a single seed Sellotaped to the letter from the seedsman! I now have a grafted A. ritteri, but would like to get one on it's own roots again when it offsets. They are obviously more available on grafts than on their own roots, since they propagate at least ten times quicker that way.

I grew the A. hintonii below from it's minute dust like seed many years ago and was lucky since only one germinated, but it survived. As you say Steve A. ritteri is the slowest growing from seed, though gains size much quicker on a graft and also offsets. A. hintonii is not as slow from seed, but still not fast. Unfortunately I never get around to photographing A. hintonii in flower. They start to flower when they produce that tuft of spines/bristles at the top.

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A friend sent me this picture of one of these observed at ELK last year and evidently are now fairly widely distributed on the Continent, so no doubt will reach the UK and USA before long, even if only as seed which is now available from some seed merchants and no doubt in a few years will be common as grafts.

A. valdezii. Those flowers are pretty tiny since I gather the seedling scion was only about an inch across.

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[Steve Johnson]

Nice plant Steve, that is in fact a pretty mature plant on it's own roots since they are naturally small growing plants. Look forward to seeing more pictures in due course.

The New Cactus Lexicon gives the normal fully grown body size up to 5cm (= 2 inches) diameter. I have seen much larger grafted ones in shows but they are not typical for own roots size. Trouble is people expect all cacti to be big plants when some like Aztekium ritteri and Blosfeldia's are just little gems that never really get large if grown naturally on their own roots, seldom getting more than 2.5cm (= 1 inch) diameter.

I used to have Aztekium ritteri on it's own roots for years but lost it in a bad winter. It came as a rooted offset from a friends plant that he grew in the 1960's when they were even less common in the UK as cultivated plants since collected plants could be imported pre CITES, even if still expensive. Therefore being slow from seed few usually bothered setting seed. Seed anyway was hard to get and expensive at the time and sold at so much per seed, therefore my friend who could not afford a collected plant on his wages actually bought just one seed from a seed merchant and germinated and raised it. He told me it did not come in a seed envelope, but as a single seed Sellotaped to the letter from the seedsman! I now have a grafted A. ritteri, but would like to get one on it's own roots again when it offsets. They are obviously more available on grafts than on their own roots, since they propagate at least ten times quicker that way.

I grew the A. hintonii below from it's minute dust like seed many years ago and was lucky since only one germinated, but it survived. As you say Steve A. ritteri is the slowest growing from seed, though gains size much quicker on a graft and also offsets. A. hintonii is not as slow from seed, but still not fast. Unfortunately I never get around to photographing A. hintonii in flower. They start to flower when they produce that tuft of spines/bristles at the top.

Thanks for your nice response, Dave. It must've been heartbreaking to lose your ritteri.

I freely admit that I'm something of a purist, and I won't keep grafted cacti in my collection. I honestly expected that I'd be able to get A. hintonii (and maybe valdezii too?) on its own roots before I could ever find ritteri in that state. So as you can imagine, what I have here came as an incredibly pleasant surprise.

A couple of items worthy of note:

1. This was the only A. ritteri own its own roots coming from a US source. When it came up as a keyword search on eBay, the other search results pointed to own-roots plants coming from Europe. Several sources were in Hungary, Poland, the Czech Republic, and Slovakia -- I think it would be reasonable to suspect that they were taken from the wild. Aside from the fact that I'm not at all thrilled by what the central and eastern Europeans are doing to poach habitat cacti, I have my doubts about how long these ritteris would last once they're put into cultivation. Growing from seed by attentive enthusiasts is another -- and much better matter. Which brings me to this...

2. My US source has his collection in West Hollywood -- can't get any more local than that! My climate isn't much different from his, so I'm sure this helped to give the ritteri a good start on the growing season. After I received it, I corresponded with him on details regarding the plant. First, he did grow it from seed. And second, it's not quite as old as one may think. While there is more to the story, I'll save the rest of it for my End-of-summer review over at Member Topics.

[DaveW]

Strangely though it has been in cultivation for so long Steve, A. ritteri is not that commonly available in the UK. The newer species like A. hintonii and now A. valdezii are more likely to be available from EU dealers as grafted plants rather than A. ritteri. Evidently it is not a commercial proposition to produce it even grafted, certainly not from seed.

How slow they are from seed is illustrated in the link at the bottom of this article by David Quail, a UK grower who raises the more difficult cacti like weeds from seed, but even his 15 year old A. ritteri are still small.

http://www.living-rocks.com/quail.htm

However it does start to offset on grafts therefore possibly they can be rooted down, or perhaps they are hard to root down from grafts which is why we do not see this done? Other plants like Mammillaria luethyi and Blossfeldia's are also usually propagated by grafting since you will have a job to find them in the UK on their own roots. They seem hard to de-graft too, even though they seem to grow on their roots OK from seedlings.

Not sure all E. European A. ritteri would be collected since they are wonderful seed raisers and have been growing A. ritteri for donkey's years. I would have thought collected plants brought across the US/Mexican land border would be more likely than being smuggled into Europe? The problem these days is CITES for importing even cultivated plants across international borders, since only one or two international cactus nurseries are CITES registered and even then the paperwork often costs more than the plant is worth.

Most A. ritteri in the UK are acquired when old collections are broken up after the owner dies or packs up. I am lucky in that I know an enthusiastic grafter who when I wanted a replacement I simply asked when he would be grafting any offsets off his mother plant. The difference in growth grafted is noticeable since it has doubled it's size in a couple of years since I got it and is starting to offset. Certainly equal in size to David Quail's 15 year old seed raised ones.

I have seen a few really large ones in shows but suspect they were grafted, as probably is the large offsetting one in this link.

http://davesgarden.com/guides/pf/showimage/52315/

I see the original description in this link below when only A. ritteri was known gives the size as 5cm (2 inches) diameter by 3cm (1.25 inches) high. Therefore plants much larger than that in shows are quite out of character.

http://troutsnotes.com/aztekium-ritteri/

Incidentally A. ritteri is the only N. American cactus named after Friedrich Ritter who is better known for his S. American cactus collections under his FR numbers. He was a geologist I believe and found A. ritteri whilst prospecting in Mexico before moving to S. America.

[Steve Johnson]

Hi Dave,

Thanks for the follow-up -- I always enjoy the detail you provide in your posts!

I understand why grafting is a method preferred by experienced growers who can use it to increase growth rates with species that are so bloody slow on their own roots. Every once in awhile, Miles Anderson offers grafted A. ritteri through his website. For those who might want to take a chance, gut instinct tells me that degrafting isn't likely to end well with ritteri or any of the other species you mention.

You do raise a good point regarding ritteris that are uncharacteristically large. Grafting is obviously one way to do it, but there's another way when plants are being grown on their own roots right from the start. A clue can be found in Trout's Notes -- "Habitat: From Nuevo Leon, Mexico growing in xeric scrub on limestone and gypsum cliffs." Limestone and gypsum are forms of Calcium, which is a natural growth inhibitor. Take away the Calcium, and it strongly suggests a theory that ritteri and other calciphyte species under cultivation can achieve growth rates that would be impossible in their native soils. Whether or not it does in practice will depend on the grower's choice of potting medium. Some people insist on including a little limestone (or gypsum as the case may be) in the mix for their calciphyte cacti. I'm not one of them, and in fact my calciphytes do remarkably well without it. The person who sold the ritteri to me doesn't either, and he said that its growth rate is 5 mm. per year -- 5 times the rate one would have if the mix included a Calcium source. I still have the emails he sent me, so I'll dig through them and let everyone know precisely what he was doing. Once again, I'll save this for a more detailed discussion in my End-of-summer review at Member Topics. Then we can find out if I'm able to match his 5 mm.-per-year growth rate this year.

[DaveW]

Yes, the question of whether cactus plants living on alkaline soils or rocks need limestone is often raised Steve. Limestone is as you say a natural growth inhibitor and our plants only tend to occupy these areas since larger faster growing plants that could overtop them and crowd them out can't. Marlon Machado, a Brazilian Botanist, wrote some time ago on the British cactus forum that limestone inhabiting plants only grow when they receive acid rain and stop growing immediately the underlying rock turns it alkaline, hence their slow growth.

As you say, plants in pots are not plants in habitat, therefore it depends whether you want maximum, if sometimes untypical growth, or to keep them looking more like habitat plants? I suppose for most of us it is something in between, faster growth but not looking like the very green overblown globes that sometimes win shows.

I know you know of the following links Steve, but for any who do not, Elton Roberts produced an article on limestone inhabiting cacti (I guess we should not call them "limestone loving" in this case). As with all things maximising growth can be overdone if it produces a plant quite out of character to it's natural form.

http://ralph.cs.cf.ac.uk/Cacti/Cactus%2 ... linity.pdf

The contrary argument is advanced in "The Stone Eaters" where devotees try and produce plants that look like they do in habitat by including limestone gravel or rocks, although seldom to the same degree as in habitat since the other ingredients in the mix often mitigate the degree of alkalinity. If you prefer this type of growth you either have to buy a mature plant or have to put up with habitat type growing rates, which means a large mature plant could take your lifetime to achieve, just as they take to grow in the wild. See:-

http://xerophilia.ro/wp-content/uploads ... Eaters.pdf

I don't think gypsum has much effect on soil PH though, unlike limestone? A quote from the Web:-

"Gypsum has little if any effect on soil pH. It cannot be used as a substitute for lime to correct soil acidity, i.e. to raise the pH."

However it can have other disadvantages:-

https://puyallup.wsu.edu/wp-content/upl ... gypsum.pdf

[C And D]

I don't have any Aztekium ritteri on it's own roots
But I have 6 grafted plants
They all have interesting patterns

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The only one flowering today
They do have many flushes of flowers during the summer

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Aztekium ritteri is the only Aztekium that is common in the US now.
I tried several times to root a cutting to no avail, so gave up on it.

Aztekium hintonii is difficult to find, and I haven't seen a single live A. valdezii of any form yet.
I'm sure a couple people have them, they just don't show or post them.

This A. hintonii is pretty old.

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[DaveW]

I picked up this lone A. ritteri f. rotundum nobody had spotted on Saturday when we went on a visit to a nursery. The others in our party went for the "normal" ones not realising what it was since it was a lot smaller than the "normal" ones that were on sale. Sorry it is a very poor quick hand held snatch shot, but the plant is a grafted seedling only the size of the tip of your finger and the grafting stock not much thicker than a pencil.

Aztekium ritterii f. rotundum GC 10005 was a name I recognised as one of Malej Jarda's names on their list. How it is supposed to differ from the normal A. ritteri I do not know. It is obviously a nomen nudum and unlikely to get published, but if it did would probably be reduced to synonymy fairly quickly.

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Mouse over the pictures in the link below to change them.

http://www.gerardo.cz/en/cacti-succulen ... seeds.html

Some of these forms were supposed to differ in whether they produced intercostal ribs, or their number. The original ritteri had one intercostal rib between the true ribs. (Intercostal = pseudo ribs in between the real ribs that bear areoles which are really just folds in the epidermis). As you can see from the various plants in this link below and in Craig's pictures above, this variation in the species was already known and probably also due to turgidity with Craig's grafted plants.

http://www.cactus-art.biz/schede/AZTEKI ... itteri.htm

Malej Jarda also list f. pentacostatum and f. intercostatum, again whether such micro splitting is justified I think most would doubt, even if we could see any significant difference to the normal ritteri. Anyway it will be interesting to compare with my "normal" grafted ritteri when it gets a bit larger.

http://www.gerardo.cz/en/184-aztekium

[Aiko]

Aztekium hintonii is difficult to find, and I haven't seen a single live A. valdezii of any form yet.
I'm sure a couple people have them, they just don't show or post them.

They were for sale at the ELK in Belgium a year ago. I am convinced more sown and / or grafted seedlings will be for sale at the next ELK in two weeks time. Seeds are easier to obtain via the Czech seed sellers.

[DaveW]

Seed is probably the only way you will get Aztekium's into the USA reasonably legally, or into many countries outside the EU. As Aiko indicates these plants are only propagated quickly on the Continent through seedling grafting, either to produce plants, or to produce quickly maturing mother plants to cross pollinate and supply seed. With all plants you buy, unless stripped from habitat, somebody has had to grow it from seed, or used vegetative propagation methods, since the days of legally obtaining ready made plants from habitat are now virtually over. Therefore either you or the nurseryman now has to raise from seed or cuttings. OK for plants that offset freely, but for most that remain single seed is the only way to go.

[Steve Johnson]

Excellent discussion, guys!

Here in the US A. ritteri is hard enough to find as it is, so I'll emphasize how lucky I was to get one seed-grown and on its own roots. I'll take very good care of this gem!

[DaveW]

A. ritteri certainly still holds the title as the slowest growing cactus Steve. Luckily the other Aztekium's seem to grow a bit faster from seed.

What we really need to find out is if the Continentals or Japanese have any secret for rooting down de-grafted plants, since that would certainly be a way to eventually produce reasonable sized plants on their own roots. The same with Mammillaria luethyi's etc.

Possibly the problem with de-grafting is cutting off the plant too close to the graft union where the vascular bundles are too lignified to root easily, rather than cutting them off higher up and leaving some remaining on the stock to produce more offsets for propagation. A bit of a job cutting higher up with scions the shape of A. ritteri though. Maybe for propagation purposes it would be a case of "blinding" the original grafted plant and then rooting down the offsets?

If you have not seen how Geohintonia's and Aztekium's grow in habitat in some really inhospitable soils, usually on nearly vertical slopes there are some videos here:-

https://www.youtube.com/watch?v=x_voav4dEWg

https://www.youtube.com/watch?v=T6_vAaIUW84

https://www.youtube.com/watch?v=hbL18Cn_FSE

[Aiko]

Aztekium hintonii is difficult to find, and I haven't seen a single live A. valdezii of any form yet.
I'm sure a couple people have them, they just don't show or post them.

They were for sale at the ELK in Belgium a year ago. I am convinced more sown and / or grafted seedlings will be for sale at the next ELK in two weeks time. Seeds are easier to obtain via the Czech seed sellers.

They were available at ELK again this year. I saw even loads of them, and the prices have dropped quite a lot since a year ago. A grafted plant of about one centimeter, flowering size (some did flower), for 10 euro. Anyone with connections going to ELK can still arrange for a plant at the last day of the three day fair tomorrow.

First time I also saw grafted plants of Mammillaria bertholdii. About 15 euro for a plant of equal size. Was quite tempting. But I don't like grafted plants, so I just wait a bit longer for non-grafted seedlings to become available.

[DaveW]

I have never been to ELK, but understand dozens of the new novelties are acquired every year by those in the EU (including the UK at present) who visit it, including collectors and nurserymen. Therefore there must be hundreds of these plants now spread throughout the EU, so they should soon be as common as A. hintonii is here now.

Grafting is a method of quickly propagating new plants, but it depends whether they are all grafted seedlings or clonally propagated from cuttings off either one or two original plants in order for seedsmen to produce commercial seed. It remains to be seen how they propagate, or will they be as difficult as Mammillaria luethyi etc to obtain seed, or to de-graft and put on their own roots?

The problem Aiko is will M. bertholdii on it's own roots be as difficult to find as Mammillaria luethyi or Aztekium ritteri are in future?