Wait. Do we know that plants are not concious?
The levels of gene expression (as in, how much of that sweet transcription and translation is happening) on a certain sample may change based on the presence or not of external stimuli, and even the genetic expression may change based on other genes' expression (see gene regulatory networks).
There is a lot of "intelligent" biological behaviour out there that is not conscious.
Now if only we could come up with some decent definition for consciousness :/
Reading the Secret Life of Trees is intriguing and makes you wonder whether we assume that other organisms are not conscious just because their consciousness doesn't look like ours. Funnily similar to how some people assume other organisms are inferior just because of superficial differences like skin color or age. Here are some great examples.
> 1. Like humans, trees give preferential treatment to family and friends.
> 2. Trees communicate with one another through scent.
> In addition to communicating chemical messages via scent, trees also use electrical signals to send messages to their compatriots via the fungi. This style of communication has been dubbed the “wood wide web” by many who’ve written about it, but the term was first used in the journal Nature.
> Wohlleben writes that deciduous trees plan reproductive cycles a year in advance. They must choose whether to bloom or hold off a year or two for the best possible results. By delaying their bloom during some years, the trees deprive herbivores that would feast on acorns over the winter from some of their food source. This shortage cuts down the herbivore population, ensuring greater likelihood of survival the next year for the seeds.
https://www.gardeningchannel.com/7-things-i-learned-from-the...
Personally, I would certainly be surprised if they turned out to have any process that can be considered equivalent to all bar one of the dozen different things that consciousness has been defined as, that one exception being the broadest possible definition of awareness of self such as to include the capacity for homeostasis… but given how poorly defined “consciousness” is, I would not rule it out.
That said, from an information processing perspective, the “Sentience Quotient” of most plants is about -2, carnivorous plants are +1, and all neuron based intelligence is about +12; this scale being log10(<bits/second>/<mass in kg>) [0] suggested that even if the limited ‘intelligence’ of plants that allows them to find ‘down’ and ‘sun’ directions could ultimately cause sentience, it still isn’t unreasonable to suggest that the scale of intelligence to reach sentience would be on the scale of entire forests rather than single organisms — a nematode worm with 206 neurons, assuming they fire 1000 times per second, is likely get as much thinking done in one second as one kilogram of petunias gets done in its lifetime.
[0] This scale has been criticised for various reasons. For amusement value only, an iPhone 12 mini is something like 14.5-15.5 depending in how many bits per operation the neural engine coprocessor uses.
The plants in entire forests (and often over much larger areas) are connected to fungus in the ground, and the fungus forms one big interconnected web upon which there is communication. If something attacks a tree, for instance, that gets communicated to other trees and they take defensive measures (if they have any they can take).
As you note, any cognition via a large collection of plants is probably slow. But trees can live a long time, and plants that die get replaced by new plants that are on the same network, so if the conscious entity is the forest itself it might have been thinking for hundreds of thousands of even million of years.
[0] https://www.cell.com/trends/plant-science/fulltext/S1360-138...
Plants are on the non-conscious list, so if they appear to have anything that appears consciousnesses like then we just rule that out as sufficient for a test of being conscious. If plants are conscious to you then the word just doesn't have a meaning/is far removed from the standard meaning.