How do they develop white on Copiapoa?

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MikeInOz
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How do they develop white on Copiapoa?

Post by MikeInOz »

I have read it doesn't develop on plants in cultivation but then I saw this video..

From 18:35 on this video ( There are more plants further back )... https://www.youtube.com/watch?v=SAdvNSeCam4
DaveW
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Re: How do they develop white on Copiapoa?

Post by DaveW »

It depends on the light intensity of your climate and how quickly they are grown. Those who often visit habitat say they often appear to only grow a few millimetres a year in some places due to limited moisture from fogs available, therefore some may easily be a hundred years old or more. Few want to grow them that slowly in cultivation though.

Copiapoa columa-alba. The white coat gradually disappears on the very old basal growth.

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These are some we saw on our trip in 2015 in the link below if you scroll down to them.

https://www.forum.bcss.org.uk/viewtopic ... 1&start=70

I still use Donald & Rowley's 1966 reunified Neoporteria excluding Eriosyce in the travelogue for Fred Kattermann's reunified Eriosyce since I do not think Eriosyce sensu stricto belongs with the rest due to different type of fruit.
SDK1
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Re: How do they develop white on Copiapoa?

Post by SDK1 »

Mike,

I've read that too and then seen poas with a nice glaucous coloring in cultivation as well. I agree with Dave, I think it's mostly a matter of light intensity. Since we know that epicuticular wax shows up on new growth as a sort of sunscreen to prevent excessive damage on the new tissue, I think it stands to reason that in the Atacama, the layer of wax will be much thicker than for a poa that's more pampered in a greenhouse.

I could also see the color of a Copiapoa species in habitat being a combination of a thick layer of wax plus some bleaching of the epidermis due to the intensity of the sun. I'd also hazard a guess that overall the coloring is due to a mixture of factors over the lifetime of the plant. Repeated weathering, lack of water, high light, more extreme temp swings than in cultivation, etc. There are some growers who've definitely been able to grow some Copiapoas with really thick layers of wax; be curious to know if they're just exposing the plants to more extreme environmental conditions or what.
5b/6a - Indiana. Half the year growing outdoors, half the year indoors.

Listening to: Periphery, Termina, Queen Kona, Veil of Maya, Knocked Loose
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MikeInOz
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Re: How do they develop white on Copiapoa?

Post by MikeInOz »

Thanks for the replies. Light intensity won't be a problem here. I wonder if I should refrain from wetting the body as well? I know they hardly ever get much rain on them in habitat.
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MrXeric
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Re: How do they develop white on Copiapoa?

Post by MrXeric »

Not the same as getting rained on, but I imagine these plants get plenty wet from the condensation of the camanchaca fog. I think between light intensity and rate of growth, the latter has a larger effect on the thickness of wax. I grow my few Copiapoa in direct sunlight, except during the summer when I need to place them somewhere where they don't get direct sun after midday or they burn (my C. hypogaea did last summer!), yet the new growth on my C. echinoidea (n.n?) is a shade greener than the older, more glaucous growth from before I bought it.
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