Sulcorebutia/Rebutia cylindrica HS44A

[Colin Walker]

Sulcorebutia/Rebutia cylindrica HS44A
I mentioned this in a thread a little while ago and have finally got around to taking its pic.

I had this labelled as Rebutia cylindrica HS44A, but the pale creamy ? pink flowers puzzled me 'cos R. cylindrica is meant to have yellow flowers. Here I think it was PhilW who gave it the name Sulcorebutia cylindrica var. crucensis, which I can live with.

The plant though is strange. It should be up to 12 cm tall, but as you can see from the ruler it's around 23 cm long. My gut instinct is to decapitate it, re-root it, with the hope that the stump might send out pups. What do you guys advise - should I take the knife to it or not? [Here we could do with a polling system. Moderators, have we got such a facility by any chance?]

Sulcorebutia cylindrica HS44A cropped small.jpg (195.6 KiB) Viewed 1803 times

[Chris43]

The next poll should be where to cut it? How much to leave for future growth.....
Nice to see white flowers on a Rebutia sp.

[Colin Walker]

The next poll should be where to cut it? How much to leave for future growth.....
Nice to see white flowers on a Rebutia sp.

Hi Chris,

I've confessed before to my colour vision impairment (red-green colour blind), hence this question: is this flower definitely pure white? I can see a feint pinkish tinge, but who am I to say?

BTW, this is now a Sulcorebutia.

[Keith H]

The next poll should be where to cut it? How much to leave for future growth.....
Nice to see white flowers on a Rebutia sp.

Hi Chris,

I've confessed before to my colour vision impairment (red-green colour blind), hence this question: is this flower definitely pure white? I can see a feint pinkish tinge, but who am I to say?

BTW, this is now a Sulcorebutia.

Well if the ruler is white plastic, you can set the colour balance from it and the flowers on top are almost white I got an average RGB 239 246 246 using the colour picker tool, the ones on the side are reflecting colour from that background.

[Colin Walker]

The next poll should be where to cut it? How much to leave for future growth.....
Nice to see white flowers on a Rebutia sp.

Hi Chris,

I've confessed before to my colour vision impairment (red-green colour blind), hence this question: is this flower definitely pure white? I can see a feint pinkish tinge, but who am I to say?

BTW, this is now a Sulcorebutia.

Well if the ruler is white plastic, you can set the colour balance from it and the flowers on top are almost white I got an average RGB 239 246 246 using the colour picker tool, the ones on the side are reflecting colour from that background.

Hi Keith,

I really don't do stuff with colour. When I was Bradleya editor, for instance, I relied on experts, i.e. the wife and daughter vetted the covers for instance.

So what d'you mean by "almost white"? Is there a bit of pink in there or wot?

The ruler is at home but I don't think that's straight white, but I will check later if I can remember.

[Keith H]

So what d'you mean by "almost white"? Is there a bit of pink in there or wot?

The ruler is at home but I don't think that's straight white, but I will check later if I can remember.

Yes Colin, a very slight bias to red though a picture against a neutral background and a known white sample or the good old Kodak grey card included in the frame is the only way to be 100%.

(I spent days at college doing this sort of thing, back in the days of film using micro spectrometers looking at dye clouds. I am fine with the Ishihara colour test but not so good on the Munsell 100 hue)

[DaveW]

Hi Colin, just looked on the Web and there is a Sulcorebutia cylindrica v. crucicensis f. albiflora HS 044a here if you scroll down a bit:-

http://www.ruegenkaktus.de/galerie3.htm

Seems to go around as just S. cylindrica v. albiflora too:-

https://www.flickr.com/photos/kakteenklaus/3659270711/

I thought when defining flower colours in botany we were all supposed to use RHS colour charts and then quote a load of meaningless numbers because nobody else was stupid enough to pay that price to buy them!

http://www.rhsshop.co.uk/category.aspx?id=10000006

[Colin Walker]

The next poll should be where to cut it? How much to leave for future growth.....
Nice to see white flowers on a Rebutia sp.

Hi Chris,

I've confessed before to my colour vision impairment (red-green colour blind), hence this question: is this flower definitely pure white? I can see a feint pinkish tinge, but who am I to say?

BTW, this is now a Sulcorebutia.

Well if the ruler is white plastic, you can set the colour balance from it and the flowers on top are almost white I got an average RGB 239 246 246 using the colour picker tool, the ones on the side are reflecting colour from that background.

Hi Keith,

The ruler's NOT white plastic but beige, or at least that's the colour my wife tells me it is. Does that help at all?

[Keith H]

Hi Colin.

The ruler's NOT white plastic but beige, or at least that's the colour my wife tells me it is. Does that help at all?

That rather throws a spanner in the works, as I was referencing the ruler for a white balance, like I said best to include a known colour patch be it neutral grey or white, 18% grey been best as you can meter of it for your exposure settings.

[Colin Walker]

OK guys, I've decided to set a deadline of July 7th at 7.00pm BST as the time at which I'll go with the majority decision to decapitate or not. If it's for the chop, the knife will be ready. If it's to keep its head I'll have a suitable pot ready and will treat it to a repot. Problem is, as is now, what happens if it's even stevens with no majority decision one way or the other? Can't half chop it's head off.

BTW I'm now calling this plant Sulcorebutia cylindrica f. albiflora since I can't find the space on a label for the quadrinomial S. cylindrica var. crucensis f. albiflora.