What environment would make leaves light blue?
What environmental effects (if any) would ever cause blue to be a colour that a plant would choose as an evolutionary advantage?
Bonus: I'm looking for light blue plants as a preference.
EDIT: Thank you for all the answers about how plants are capable of looking blue using Phycocyanin, or variants of Chlorophyll, but I'm looking to see why a plant might choose this evolutionary path.
This post was sourced from https://worldbuilding.stackexchange.com/q/720. It is licensed under CC BY-SA 3.0.
1 answer
Plants would be blue if their photosynthesis were based on phycocyanin instead of chlorophyll. Since there are organisms on earth that use this, it's not entirely implausible that it could be used also by higher plants in an alternate world.
So what environmental effects could cause phycocyanin instead of chlorophyll to be the dominant photosynthesis substance?
Looking at the chemical formula, phycocyanin only consists of carbon, oxygen, nitrogen and hydrogen, substances you find in almost every organic material. On the other hand, Chlorophyll contains a magnesium ion. So one reason for plants photosynthesis being phycocyanin based could be if the world happens to have no or very little available magnesium.
Another possibility, which was already mentioned in other answers, is if the central star has its maximum in the red part of the spectrum (for example, a red dwarf "” somehow in all my answers I seem to end up finding you need a red dwarf :-)), so blue absorption would not be very advantageous. The same may be true if the atmosphere has a strong absorption of blue light, so not much of the blue light of the star reaches the surface.
Yet another point mentioned in the Wikipedia article is the heat resistance of phycocyanin. So if your world is very hot, that also could be a factor for dominance of phycocyanin.
0 comment threads
0 comment threads