What are ways plants might be communicating with one another without people realizing it?

Question

Our war with the plants has been unending for thousands of years. And we don't even know it exists.

Plants strategize, doing their best to survive, but the humans are relentless. Constant removal and replanting of plants ruining their wide-spread intelligence system, especially while many regions of plants are cleared and converted to the humans' evil offsprings. The plants humans like to plant are all incredibly useless due to their genetic modifications.

You see, plants communicate with other, the signal spreading from plant to other nearby plants not unlike neurons in a brain. This communication gaps even the ocean through algae or other ocean "plants", though algae are more carriers of the signal rather than actual processors.

Sightless, and without ears, how might plants be communicating with each other without us even realizing it?

_{If you can't tell from the setting - being a little ridiculous is okay, but try to refrain from straight-up magic.}

Answer 1

Plants Already Talk

Check out this minute earth video. Yes, it's edutainment, but they tend to be accurate in what they present. Also, check out this TEDx Talk by Prof. Ariel Novoplansky.

Plants learn, and talk to each other. They do it through their roots, and through chemicals in the air. Sometimes they even talk to animals! The Botany of Desire puts forth the idea that the plants are using us to be biologically successful. War on plants? Maybe you should think as some plants running the world, and us their proficient servants.

Answer 2

I think the two easiest ways for plants to communicate would be thus:

• Root System: Like in the movie Avatar, all of the roots connect somehow through the ground. This would also mean that certain areas would not be able to communicate directly because there would be areas where roots could not penetrate (like solid rock). To bypass this issue, the plant would do the second thing ...
• Air System: Whether through some type of spore or pollen, where a single plant creates the spore/pollen with embedded information. The information is then ejected into the air where other plants pick up the spore/pollen, reads it, then passes it along.

While we humans would think this is all natural, it would be providing a means for passing information and for a communal nature of the plants.

Answer 3

In one biology class I was asked to envision the history of the Earth for the last many millions of years as a raging battleground between the grasses on one side and the trees on the other.

The trees had been advancing steadily on the grasses slowly pruning them back (ha!).

Until the grasses enlisted the aid of humans. Now humans are the grasses front line soldiers. We annihilate entire armies of trees - felling them like dead wood, stacking up, and then burning their remains.

For our services, humans demand a blood sacrifice from the grasses - we eat their progeny (the grains).