Subject: Black leaves

From: [email-masked]
Date: 12 May 1995 16:07:39 +0100

Black leaves are not uncommon.  Everybody knows the dark-red varieties
of Prunus and Beechwood.  The leaves of these plants look quite brown, e.g.
very close to black and the trees do not show any impairement.
In these cases however it seems that leaves are rejecting not just green but
also red,and the mix of green + red is brown. So the trees shouldn't have
a problem of overheating.
There is not clear reason why plants are green and not black, or brown. But
probably the reason is in the phylogenesis. Terrestrial plants originated
>from  chlorophyta, e.g. from green algae and still are green as those weeds
are.
What do you think ?
Fernando

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From: Nancy Harrison <[email-masked]>
Date: Sun, 14 May 95 08:28:05 -0500

>from chlorophyta, e.g. from green algae and still are green as those weeds
 
which evolved from a cell with symbiotic monerans with Chlorophyll a & b...
so it just happened, I guess!  But it is the infra-red that would heat up
the leaves, so maybe it doesn't matter what color they are. The red
pigments, as I understand it, are absorbing in the blue part of spectrum
which is the light green leaves use the most of. - Nan in Calif.