As Ian hasn't replied, may I suggest just having a web search for "facultative CAM" and you will find plenty of references. The first link in my previous postD^L wrote:Interesting notes about CAM in mesembs, Ian. Do you have a reference I could persue?
"Drought-stress-induced up-regulation of CAM in seedlings of a tropical cactus, Opuntia elatior, operating predominantly in the C3 mode "
http://jxb.oxfordjournals.org/content/e ... rr106.full
also has a number of references in the introduction to facultative CAM but whether they are available online I do not know.
In my recent searches I had been looking specifically for cactaceae but did come across a good number of papers that did mention facultative CAM in other succulents, of course I did not save those links.
graham