Oh, I think you mean the capillaries? (The tiny vein-like connections through which water, gas and sugar flows.) I suppose if you're wanting to poison a plant, you can always put in bad chemicals through the roots. But there are other ways to hurt a plant also.
Here
might be some handy tips for this. Or here.
edited 6th Dec '10 10:47:59 PM by QQQQQ
Plants don't have a brain, and they don't have nerves. As far as I know they don't have any centralised control.
The only thing I can think of that would kill a whole plant in an instant would be blasting it with fire. Poison would be very quickly absorbed by roots, but it wouldn't be instantaneous - and you would have to get almost all of those roots, too.
I've seen experiments where they uproot a plant and separate its roots into two clusters. one of these clusters in a jar of red dye and the other in water. The next day, the plant was half red and half green. Not a neat down-the-middle split, more like piebald. My point is that they don't centralise things. They don't have a heart that they route all their sap through or anything.
General plant biology... hmm... OK, there are two major processes. Sugar is produced in the leaves and goes down. Water is absorbed by the roots and goes up. The leaves take in light and carbon dioxide and produce oxygen, which is expelled, and sugar, which travels down to the rest of the plant. (I could probably go more into detail about this, but I figure you don't want all the specifics and jargon)
All signals in a plant go by chemicals - this means they respond slowly, because a chemical is not as fast as an electrical impulse. If you want your tree to be mobile, generally plants aren't terribly coordinated when they move. They respond to a stimulus, such as more light hitting one side of their stem than the other, or a touch, or gravity. They don't integrate the signal or decide what to do with it, they just have a predestined response.
edited 7th Dec '10 1:10:26 AM by LoniJay
Be not afraid...Wait so if we cut a venus flytrap plant somewhere above the roots the rest of it would still be alive and act the same way then??? I'm still kinda confused.
edited 7th Dec '10 1:35:48 AM by PsychoFreaX
Help?.. please...Pretty much, yeah. If you cut off all the traps (and most venus fly trap plants I've seen have more than one) it might die eventually from a lack of nutrients, or from an inability to photosynthesise. But more likely those traps would just grow back.
That even happens with trees. If you cut a great big tree down, saw it off at ground level... come back a few weeks later and it may be putting up shoots from the stump.
edited 7th Dec '10 1:49:39 AM by LoniJay
Be not afraid...Thanks
I guess I have to think a lot more about the next part of my story now. Which is getting really difficult. But at least now I know better.
So, is the tree magic? Or alien? Or were you going for a scientifically plausible plant? Does it have to actively attack things?
You might want to look at things like the carnivorous plants called sundews
, which move. Or things that grow on trellises like passionfruit vines or beans. See, the reason their tendrils twine around things is because they sense pressure when they touch a wire, and that causes it to grow in the same direction. If you were to speed that up it could be an attack. Or perhaps rather than direct touch a plant could have tiny hairs that sense air disturbance and lunge towards movement.
I don't know what you're trying to do, but maybe that will help?
edited 7th Dec '10 2:12:26 AM by LoniJay
Be not afraid...Well one of my villains used their mystical energy to grow the tree and used it to fight a character of mine. So I guess that would count as magic. The mechanics of how it's done is still WIP though. But I'll try to figure it out soon.
Help?.. please...

So now there's a part in my story where some of my characters have to deal with a monster tree plant thing right?
Now what I want to ask is this. Is there a part in a tree plant or whatever, where damage could kill the rest of the tree? I'm guessing somewhere around the roots but that's just a hypothesis.
So I know that planst have a biological system of absorbing energy from the water and sun and using it to grow. But is there a certain part in plants that organizes those biological systems? Or even allows a venus flytrap to respond with it's instinctive attack? Like a plants equivalent of a brain or something?
If there is then where would that point be in a plant? I'm just not quite sure about this. If not then I would just like to ask how else a plants biological system work.
edited 6th Dec '10 10:31:58 PM by PsychoFreaX
Help?.. please...