Some people say trees are knot smart, they’re just board.
IQ is just the square root of the diameter. You’ll find that most of them are saps.
Use a measuring stick.
Communication is just data transfer and requires no intelligence. Every cell in our body is communicating via hormones; they aren’t intelligent. And even a virus can kill for its own benefit; again, no intelligence needed.
I once had a tree that was completely impervious to infection.
So of course it started thinking it was pretty tough and it developed quite an aggressive attitude.
But despite its extremely tough exterior, deep down it was an old softy.
And that was the root of the problem: it was all bark and no blight.
Well, I said we were drooling imbeciles. 
On a tangent, this is an example of why I think it’s very unlikely humans will ever discover “intelligent” life in the universe. Even on our own planet, there are modes of life so different than ours that it renders the question meaningless.
And some people don’t know their ash from a hole in the ground.
Most organisms that kill do it for their own benefit.
The term, “intelligence” has meaning. There might be a majority of creatures that have reasoning systems that are completely useless or bizarre so far as we’re concerned, but anything intelligent, we should be able to understand and relate to, to at least some extent, since intelligence implies logic and logic is pretty universal.
:dubious: Among whom or what? Excluding humans, that is.
A tree could seem marginally intelligent to us if we watched its whole life on fast-forward. If we watched these videos of multiple trees, one might look more intelligent if it dealt with poor growing environments better than another.
There’s no clear border where sentience manifests in an observable and objective way. But reasonable people will agree that trees lie on the non-intelligent side of that fuzzy line. (Barring unforeseen botany, anyway.) Intelligent systems selfjoin into being in organisms that are complex due to being made of really numerous and diverse elements.
So a tree doesn’t have intelligence. An apple grove probably doesn’t. But a large forest’s ecosystem… maybe something like that does. Things like that certainly act like they have intelligence. Thank god they’re slow enough to avoid developing gossip and formalwear.
What!!! Have none of you seen Avatar?
Ok. back to business.
Not to mention an anthill. Any individual ant has the mental capability of an . . . um . . . ant. But collectively, could you say an ant colony is “intelligent”? If so, how would you communicate with it?
“Of course I’m sane, when trees start talking to me, I don’t talk back.”
― Terry Pratchett, The Light Fantastic
You know who the real monster is? Man…grove trees
OK, I did an experiment: I gave a standardized IQ test to my tree with a standard No. 2 pencil.
After the allotted time, I noticed that the tree had not picked up the pencil. Normally, one would assign a very low score to this, but calling my friend, a professor of ethical behavior in plant, he suggested that this demonstrates an extremely high degree of empathetic behavior, as the tree obviously reviews to use a wooden product.
We can safely conclude the tree must be highly intelligent.
Or that the test is fundamentally flawed, but that can’t possibly be true, right?
Don’t believe a word that pussy willow says.
Which branch of education are yew referring to?
Sorry, you lost me here