Duality

I haven't heard of plants that induce fire in themselves, but I'm sure there are plenty of chemicals that freeze to look like ice but are also flammable (although, not involving ice, there's no real antithesis involved there). Photons don't have charge and neither photons nor atoms have a property that 'flips' in an antithetical way as far as I'm aware, although other particles can flip charge fairly readily if you choose the right ones in the right conditions. If two photons collide you get a positron and an electron (positive and negative charge, respectively) and vice versa, if that's what you have in mind. Other than that, I'm not sure if there are any other examples of this sort of invert-dualism process, nor what the base concept involved might be called. 

I do seem to recall.... somewhere, it being said that lightining doesn't strike the ground. That the electron charges in the ion heavy atmosphere reverse charges, weaken some room for more electrons to be affected and kinda sorta wedge downward, then back up to the cloud and filling up this space with the light energy as it wedges itself further downward till it hits ground and disperses. That the Lightining functionally ping-pongs between cloud and ground several million times all faster than the mortal eye can follow and we just see it as one flash with supposed defineable zigzag pattern.

 I feel that process would have a name. Induction? Would help if I could remember what an Ion was.

 Seem to recall a mushroom you could snap off a tree, light and use like a torch.

 See, this is the trouble with thinking several dozen simultaneous thoughts. They stir together sometimes.

 Pancakes. 

Lightning is still somewhat ill-understood in several aspects, but the essence of it is that positive and negative ions (ions = atoms that have lost or gained a few electrons so they have an overall charge) in a thunderstorm separate, with positive ions going up and negative ions moving closer to the bottom of the storm. The buildup of negative charge at the bottom of the storm (coupled with the fact that the earth is usually positively charged overall) causes a flow of negative ions to emerge from the bottom of the storm and move towards the ground. This initial current is not as easily visible - the bit that's all flash and bang is when the flow of charge from the cloud touches the ground to form an electrical path, allowing the ground's positive charge to move back up the path and discharge positive ions into the cloud at the same time as the cloud discharges negative ions into the ground. It only ping-pongs once, but that once is plenty more than enough for it to fry anything in its way.

Oh, yes, there are plenty of flammable mushrooms. They feed on decay byproducts, which usually include methane gas and other such easily ignited substances. They're also quite nice toasted if you find any edible ones.

I would advise thinking several dozen simultaneous minds to think those thoughts individually, but you already seem to be doing that with all your OCs.