In article , DaveDay34
writes
There seems to be much confusion about ivy. I'm not sure that I want to go
into all the details and explain it all to those who don't understand, but I
think it's enough to point out that to be a scavenger you have to be able to
recognise that something's dead, and that it can therefore be 'scavenged'.
Plants (including ivy) are unable to make this distinction. Put simply, plants
don't 'think' in the way we recognise that animals can.

Some years ago urg had a long and contentious, though mostly good
natured, discussion in a thread called 'A philosophical approach'.
That discussion centred mostly on how plants were believed to act and
react. It revealed some deep seated unease among urg contributors about
the matter. It emerged that little proper research has been done in the
area, though there is quite a lot of literature available to 'prove' all
viewpoints held. I would appreciate details which show that plants
cannot distinguish between something living and dead though, that is a
new theory to me.

I agree that plants don't think. That is because they do not have a
brain. They also don't see or hear because they don't have eyes or ears
etc. etc. As living beings though, they carry out all the functions of
animals (including humans) other than moving about, but they do it by
different means. For example, though plants do not see with eyes, they
are able to detect direction of light, and they are able to work out how
to react to light. They have their own ways, different from animals, of
eating, drinking, creating a habitat, procreating, protecting themselves
and their species, adapting to their environments and evolving. All that
requires some very sophisticated form of intelligence, equivalent to
though different from that used by animals.

Plants are entirely independent of animals for their survival, they were
around on this planet long before animals developed. Animals however,
including humans, are totally dependent upon plants directly or
indirectly for their food and for almost all other things they do. In a
world of food shortage, a better understanding of plants and how they
operate could be of great benefit to us all.
--
Alan Gould