> Plants are our cousin eucaryotes, and they've been evolving as long as we animals have

That is true. And look how different we’ve become.

> and so there is likely to be equivalent information processing complexity to be found in them

That’s quite a leap. I think precisely because plants and animals have evolved separately for so you can’t make that assumption. Maybe plants hasn’t not simply because they don’t need to, as a fundamental consequence of their differing physiology.