In article ,
Roger Tonkin wrote:

Neighbour has this copper coloured shrub, about 1 meter high.
It is an evergreen (or should that be evercopper!) but just a
few shoots have a mixture of copper and some green leaves. He
is no real gardener, these were planted for him, but wonders
why - so do I.

Pictures are at:

https://picasaweb.google.com/1043284...40020407/Bush?
authkey=Gv1sRgCObny-Ds4vaecA

Pictures 1 & 2 show the green area. There are both green and
copper on the same branch. The green leaves seem to have
started yellowing a bit (Pic 1).

Picture 3 shows a bi-coloured leaf

Picture 4 shows the whole bush

It is possible that real experts know, but this is just one of the
many ways where plant genetics and development are very different
from animal, and poorly understood. Plant cells have a 'cellular
memory' (a.k.a. are differentiated), but many or most are also
totipotent (i.e. can develop into any other type of cell). That
also applies to many colour variations, growth habit (e.g. bush
ivy) and other properties. Also, their meristems (growing cells
at the tip) are usually free of viruses even in virus-ridden plants,
and sometimes de-differentiate (including changing colour and
growth habit).

I.e. plants do that sort of thing, and nobody seems to know why.
Gardeners call it reversion, which explains nothing.


Regards,
Nick Maclaren.