Red epidermis

Hi out there this is Greenhouse.
  I've been growing Cactus for over 20 years in the UK,I now live in Australia and trying to start a new collection, and I've come across something I've never encountered before, a lot of the plants I've acquired have red epidermis, were as the same plants are green in the UK except those that are naturally brown. What I'm trying to find out is what affect this has on growth and flowering.

High greenhouse! Welcome to the forum and welcome to Australia! Red skin colouration can have a few causes and in some cases is a genetic trait. Gymnocalicium damsii is one such cactus that when dormant turns a red colour and when actively growing is a green colour. Are you able to post a picture?

Hi SneakyCuttefish
Thanks for your prompt Reply to my post, you say Gymno damsii has a red colouration when dormant and I don't doubt what you say is right but I've never come across this even in damsii.I can't post a photo at the moment as I'm away on holiday. Thanks for the welcome to Australia

All good mate. I would love to see a pic when you get back. I have notice some of my other gymno's and echinopsis (lobivia) crests turn red when they are water/heat stressed as well. I will post a few pics when I get a chance.

Here are a few pics of some plants that are currently displaying a red skin colouration. These plants are all water stressed as it is just nearing the end of winter and they haven't had a drink for a couple of months.

Lobivia crest


This gymno sports red coloured pups all the time and the main head will turn the same red colour if I really stress them over winter.

Another smaller gymno. Same species.

This is a young echinocactus grusonii that hasn't had a drink in months. It has a more reddish/purple tinge to it.

Hi
  Thanks for your Pic's it looks to me as this is something I will have to get use to .I just got a reply to an Email I sent to John Pilbeam quite an expert on Cactus, and he reckons it could be due to the different conditions in Australia ie a drier atmosphere as in the UK it is damper all year round, so they wouldn't get so dry, may be this is the answer

That is highly likely. The red colouration will go away if I give them a water. I would say it is a probable combination of more intense sunlight and water stress. It doesn't seem to bother the plants in the long term and could very well be a survival mechanism. By reducing the amount of chlorophyll in the epidermis the plant would photosynthesise less and therefore use less resources like nutrient and water. Especially considering that the former is not available without the latter.