Thanksgiving and Christmas cacti

[fanaticactus]

In case anyone is still a bit foggy on the differences between these two "holiday" cacti, here's an article from Dave's Garden that explains it all very simply with a short narrative and several excellent photos. http://davesgarden.com/guides/articles/view/3472/" onclick="window.open(this.href);return false;

[DaveW]

That illustrates the advantage of getting used to always using their proper Latin names rather than common names, since there is then no confusion.

For instance bluebells - the American bluebell (Mertensia virginica) is different to the English bluebell (Hyacinthoides non-scripta) is different to the Scottish bluebell (Campanula rotundifolia) is different to the Spanish bluebell (Hyacinthoides hispanica). Therefore just calling them bluebells can mislead people from other countries, or sometimes even other areas of the same country.

Many "Old World" names were simply applied to things in the "New World" when settlers applied them to things that looked similar to old world species, though often not even related generically, sometimes not even in the same family.

Useful article if people note their proper names and use those instead.

You may find this article useful too as it includes the other similar epiphytic cacti:-

http://cactus.biology.dal.ca/paulS/chri ... stmas.html" onclick="window.open(this.href);return false;

[fanaticactus]

Thank you for that link, Dave. It has a lot more details that we more avid growers appreciate, such as water acidity, how to treat for mealies (both regular and root), and, as you mention, it also addresses the "Easter" cactus group with good details and descriptions.

[majcka]

Can you imagine a confusion in my country since we dont even have a Thanksgiving. We are in that way lack of one species.

Or even better/worse we have two different plants named Christmas cactus.

[fanaticactus]

Well, Maja, I just searched your calendar of Slovenian holidays and found you have one on 25 November. So you can call the Schlumbergera truncata your "Rudolf Maister Day Cactus" ! Of course, non-Sovenians will not know what you're talking about. It'll just be our secret!

[majcka]

Well, Maja, I just searched your calendar of Slovenian holidays and found you have one on 25 November. So you can call the Schlumbergera truncata your "Rudolf Maister Day Cactus" ! Of course, non-Sovenians will not know what you're talking about. It'll just be our secret!

Fine. I have one Rudolf Maister Day Cactus ready to flower with one whole white flower just one of this days.

And if we wanted to be our secred you should told me that in a PM.

[oldcat61]

Can the color of the hybrids change with growing condition? Light, fertilizer? Last January I bought what was sold as a white Christmas cactus. 75% off because it was after the holidays. It was a nice fat plant & still had buds, so in the cart it went. All of $3, if I remember. The buds opened 2 weeks later, a lovely white with purple stamens(?). Now it's blooming again, very heavily, but the flowers are yellow. Am I crazy? Sue

[fanaticactus]

Wow, Sue! That's very unusual (I think). I'm hoping someone who's more well versed in hybridization will chime in here, because I've never studied the finer points of cross pollination, fertilizers, etc.--all of which I'm sure would greatly help my appreciation and success with this crazy hobby. I suppose they can be pollinated even by houseflies visiting one flower after another. I'm still naïve enough to want to cross pollinate an Echinocereus with a Parodia (or Rebutia, Ferocactus, Thelocactus...whatever). I suppose any number of things might trigger a change in color. So I really hope someone with a better understanding of these things will catch this thread and explain the possibilities for us.

[luddhus]

Can the color of the hybrids change with growing condition? Light, fertilizer?

Yes, the colour of especially white and yellow Schlumbergera flowers often turn more pink when growing conditions change. Low temperature is said to be the cause, even if my own observations have been somewhat inconclusive.

[DaveW]

Yes Sue I have read the same in the past as luddhus there was an article in a past British cactus journal on it, probably by Will Tjaden. The white "Christmas Cactus" flower colour is temperature sensitive and can change from white to pale pink according to the temperature when the flowers are being formed. I did not know there was one that went yellow though too.

Regarding "Christmas Cactus" in the UK. When I started in the 1960's the plant misnamed by most collectors in the UK as Zygocactus truncatus was in fact "Buckleyi" without the toothed segments. Only later did the hybrid truncatus types become common with the toothed segments having claw like tops to the joints, so living up to the name "Crab Claw Cactus". Therefore "Christmas Cactus" can mean different things to different collectors around the world.

[oldcat61]

Here's my yellow one. Wish I could find a decent photo from when I bought it. SUE

[fanaticactus]

So, luddhus and Dave: Once a white Zygo turns yellow (or pink), is there a chance of it reverting to white based on growing conditions that particular year?

[DaveW]

As said it's temperature related when the buds set. Possibly if it flowered more than once a year changing the temperature it was kept at may alter flower colour, but usually you would have to wait until a new crop of flowers next year. I can't remember whether it's higher or lower temperatures that produce white flowers, maybe luddhus knows?

[luddhus]

Low temperature should produce more pink flowers. I have observed this on indoor plants where flowers on segments close to the (cold) window have been more pink than the rest. On the other hand I have had flowers in spring with almost no trace of pink, and those buds should have been formed in even lower temperature.

[DaveW]

I enquired on the BCSS Forum if anybody knew the article I remembered and MikeT kindly gave me the reference, so I will look it up and may be able to copy it for you Sue. It was in fact by a chap called McMillan, like Tjaden another UK epiphyte cultivator. Mike T says:-

"The March 1993 Journal (Vol 11 no. 1) has an article 'Colour Development in Schlumbergera' by A J S McMillan. There are pictures of a white flowered cultivar, 'Dorthe'. Flowers developing at minimum temperature of 15C are white, but some pink developed at a temperature of 12C. Even 1 minute exposure to a temperature of 10C results in some pink, 9 minutes leads to a stronger pink. He gives details of other white and yellow flowered cultivars exhibiting the same effect."

Evidently to keep the flowers white you need to ensure the plant is never in a temperature below 15C (59F) when developing flowers.