November 2017 - Schlumbergera truncata

[Grimm]

As no one has posted anything for this month, I thought I'd have my first go at one of these. I chose Schlumbergera truncata or the Thanksgiving Cactus, which was also cactus of the month in December 2007 - viewtopic.php?f=8&t=6442&p=49610&hilit= ... era#p49610
Unfortunately those old posts can't be added to So hopefully it is okay to effectively re-post In any case, I think this classic cactus should be November Cactus of the Month every year December should be left to the "true" Christmas cactus, Schlumbergera x buckleyi

As the old post says, this is an epiphytic forest cactus native to Brazil and other South American countries that likes airy, organic, composts that mimic the material that catches in the crooks of trees etc. I actually struggled to get mine established until I tried coarse organic (peat free compost with the fine material sieved out, leaving a rather woody mix) with about 1/3 aquarium gravel, similar to what templegatejohn suggests in the 2007 post.

Most of us, at least here in the UK, probably have or have had one of these given the supermarket's tendencies to practically give them away and they are available in quite a few cultivated colours ranging from the original red, through peach, to white. They grow well in slightly shaded spots, and aren't particularly large plants, and so can fill spaces in our houses that are unsuitable for most desert cacti.
They can be relied upon to flower every year even without fertiliser, and many people get them to flower twice a year, although this isn't something I've seen myself yet. Mine also flower in December, whereas most in the UK seem to start in late October.
They're also fairly tough as long as they don't get cold, although I've noticed a habit of dropping flower buds if they're in an environment where heat and/or humidity changes rapidly (like my small kitchen). Even if you manage to kill off the roots by over-watering, vegetative propagation is quite easy. I've no experience with seeds or fruit, although I expect it probably grows very easily from seed if it is anything like it's close relative Rhipsalidopsis gaertneri (the Easter Cactus) - if anyone can enlighten me, I would be very grateful

The photo is from last year, of a single young plant with red flowers. I also have a larger pot with three larger red flowering plants in, and a pot with three very young white flowering plants.

[DaveW]

Yes apparently they don't like a change in conditions when in bud, therefore moving them at that time to different conditions can sometimes cause bud drop.

Unfortunately the plant has been hybridised in cultivation so it is difficult to know if the original habitat introductions are still in cultivation. However with a plant that is usually vegetatively propagated from stems it is likely to be, unless as with some of the other early epiphyte introductions like Disocactus ackermannii the hybrid "Epiphyllum ackermannii" survived and was mistakenly passed on as the true Disocactus ackermannii, when it like the more tender habitat species were killed off in "the Big Freeze" that occurred in Europe around that time therefore usually only the more hardy hybrids survived. However knowing which plants are "true" is now almost impossible unless you can obtain a start of authenticated collected material once again. For years the truncata/russellii hybrid = S. X 'Buckleyi' was grown as the true S. truncata in Europe.

https://davesgarden.com/guides/articles/view/392

I did manage to obtain a cutting from a plant claimed to be a collected clone of S. truncata originating from Countess Orssich in Brazil (who also collected S. orssichiana, which was named after her). Sorry a poor photo, it was a hand held snatch shot since I did not have time to set up a tripod as I had other things to do when it flowered). However you can compare with plants normally in cultivation and Graham Charles original illustrations in the link below..

The problem is flower colour is said to be slightly variable in the wild, therefore even the different habitat collections when first discovered and sent to Europe could have slightly variable flower colours. Add to that the fact people will keep hybridising cacti, therefore it is hard to determine which plants in cultivation are actually still clones of habitat material, or originally from habitat seed. I suppose if you are not a "purist" like me and grow plants solely for their flowers, then hybridisation does not matter.

Schlumbergera truncata Countess Orssich clone.

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There is a good article on S. truncata by Graham Charles in Cactus Explorer No. 13, pages 12-15, showing the early artists colour plates of S. truncata, which even allowing for artistic licence does indicate there was some variation in flower colour in the original clones.

You can download Cactus Explorer No.13 here:-

http://www.cactusexplorers.org.uk/journal6.htm

Interesting that Grimm's flower looks more like the illustration Fig 2 of Hooker's designated as the neotype, whilst my flower looks more like Fig 3, said to have been grown from collected seed from Brazil by a Mr. Hood in 1823.

The illustration Fig. 6 seems to be S. russelliana, or a hybrid of it, since it has no "teeth" on the segments and not a zygomorphic flower, but the "flower in flower" type of tiered regular flower with the first segments spreading then another flower seeming to come out of them..

http://cactus-epiphytes.eu/z_page_schlum_russell.htm

[7george]

Here is my plant (3 in one pot) too, photos from today. Hope to see its flowers in a few days.

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Schlumb_287.JPG (171.13 KiB) Viewed 5378 times

[Nic]

I would have photos to share but mine did not survive the move west to well, though a few did manage to produce fruit, though it will take them a few years to return to a decent size.

[Grimm]

Interesting that Grimm's flower looks more like the illustration Fig 2 of Hooker's designated as the neotype, whilst my flower looks more like Fig 3, said to have been grown from collected seed from Brazil by a Mr. Hood in 1823.

Interesting indeed! I thought the odd appearance of my flowers was due to excessive cultivation, it didn't occur to me that it might be a common characteristic in wild populations (would be good to see habitat photos to confirm, I'll have a search around the web for some). I bought them from one of the supermarkets a few years ago, so they could be of any origin. They also have smaller stem segments than my white flowered plant, although I'm not sure if that means anything

I forgot to say in the first post - they can be used for seedling grafting! I managed to graft a variegated Astrophytum asterias seedling semi-successfully onto one - the scion attached and grew, but then I think I took it out from the humid environment too soon and the joint failed, killing the Astro. I haven't tried again since.

[DaveW]

Yes not tried grafting seedlings on Schlumbergera pads, but a friend did and was happy with it. Here is the video that started it:-

https://www.youtube.com/watch?v=kuj5b9xTg2U

Misguided conservationists. I was told by David Hunt that conservationists in one part of truncata's range in Brazil were worried the local population were taking too many truncata's from the wild for home decoration, therefore decided to reintroduce some. However instead of taking plants from the area, breeding them and then reintroducing them, they just went out and bought a load from cactus dealers, plants of unknown parentage and probable hybrids and introduced them and so polluted the habitat gene pool in that area..

[stefan m.]

That was eye opening. Maybe i should try it.

[DaveW]

You could probably also use Schlumbergera for tubercle grafting in the same way as seedlings Stefan instead of Opuntia's, as in this video.

https://www.youtube.com/watch?v=HA3ZIjHGKZ0

[stefan m.]

But for that i need a plant with tubercles, and the only one around(thats not a seedling) is mammilaria. And that ones my least favourite cactus. Also ive seen that video before, but im certain that unlike schulmbergera, opuntia has multiple vascular channels inside it, and tubercle grafting is riskier than seedling graft, so probably not worth it right now.

[DaveW]

The vascular bundles on cacti are usually in a circle around the centre core and vary in size with the diameter of the stock, hence a small scion on a large stock has to be placed off centre to contact them. In flat padded Opuntia's they are in a very flat oval or ellipse, which is why in the video he staggers the tubercles to contact the vascular bundles rather than placing the tubercles centrally in the thickness of the pad. I have never examined a Schlumbergera cutting to see if the vascular bundles are circular and central, or elliptical as in an Opuntia pad?

One reason for scions not taking if they are small on a larger stock is automatically placing them centrally rather than crossing the vascular bundles, even if that means offsetting the small scion on the stock, as explained lower down these links.

http://pereskiopsis.com/cactus-grafting-guide/

http://www.teesside.bcss.org.uk/BCSS/CU ... afting.htm

Anyway I did not mean to deviate from the Plant of the Month theme, just adding to the comment that Schlumberger cuttings could also be used for seedling grafting.

[cactidan]

I have used schlumberger hybrids for quick grafts to save a seedling or small pup before, easy to work with and easy plants to keep around. I don't graft plants normally but it can be useful at times. Anyway back to the topic the only SPECIES I grow is S. opuntioides. Lovely genus and thanks Dave for highlighting the actual species.

[Shmuel]

Thanks for posting this as November's plant! For some reason I have had terrible trouble growing these. I have hundreds of cacti and no problem, but Shlumbergera defies me. I have no problem with Rhipsalis or Hatiora or Aporocactus but these defy me! And supposed to be easy. Perhaps it is winter cold - I am in USDA zone 9b, or lack of or too much sun. I used a cactus epiphyte mix I make.
Any suggestions are appreciated.
Do you grow them inside or in greenhouse conditions? Does Zygocactus still exist as a name?

Shmuel
Jerusalem Israel

[stefan m.]

Shmuel schlumbergeras are easy, if you live in temperate climate. They like partial sun to shade, and high humidity. They also need a cool period to flower.

[DaveW]

Any genus correctly published still exists as valid genus. Whether you use it is a matter of opinion as to what classification you use. Botanists are always sorting and resorting plants into different genera and it is unlikely the process will ever stop.

Zygocatus K. Schumman in Martius Flora Brasiliensis, 4-2, 224, 1890. type species Epiphyllum truncatum

Schlumbergera Lemaire, Rev. Hortic. Ser. iv. 7, 253 1858 type species Epiphyllum russellianum

Obviously if you lump truncata in with russellianum, Schlumbergera takes priority as the oldest generic name available. That means you cannot put russellianum in Zygocactus, since it being the type species of Schlumbergera and being published earlier Schlumbergera would immediately take priority over Zygocactus. If you keep truncata in a separate genus away from russelliana though you can still call it Zygocactus truncatus.

Just a case of the oldest generic name available takes priority in any combination of genera.

[Grimm]

Any suggestions are appreciated.
Do you grow them inside or in greenhouse conditions?

Mine grow indoors behind a net curtain, so they don't get much light. Humidity is also high here, running between 60% and 80% at the moment according to the weather report (my dehumidifier says 50%-70%). As soon as the flower buds showed I moved it to a part of my living room that has virtually no natural light, and it's still happy (so far).
As I said above, I struggled to get my truncata established, but once it was it has been easy. The young roots are very prone to rot, as with many cacti, as they can't take up much water.

You might want to try the hybrid Schlumbergera x buckleyi as, in my experience, it's much tougher (probably hybrid vigour) and grows a substantial root system more like a desert cactus and so is less sensitive to watering conditions. I don't have many Epiphytes but of all the ones I have, S.truncata was the most difficult to get established.

Do you know anyone else in the area that has had success with them? It could be that Israel is just too arid/dry for them.