Do trees feel pain?

Is pile driving the arboreal equivalent of a trip to the dentist – a little root canal treatment, maybe, with that slow-bore drill they use to grind your inner tooth’s still tender pulp? And just as my toes curl at the very thought, is it also true Acacia trees can curl up their leaves at the approach of a perceived enemy or threat – into an embryonic ball, like Basil (Fawlty) at the approach of The Psychiatrist? Yes, maybe, perhaps – with a little imagination and healthy dose of anthropomorphism: it’s certainly not a far reach from the findings in the new field of Neurobotany we were treated to in a seminar at Kew last week. Plants evidently see, hear, learn, remember and then even “decide” (whether or not we feel more comfortable adding the inverted commas) how to respond to events or stimuli. Roots can even tell whether nearby fellows are self or other and, if other, kin or stranger. Needless to say their responses to such encounters are all too similar to our own. The jury is out though on the question of pain: the plants and their root systems, in particular, may exhibit a form of collective consciousness, more akin to a swarm or network than an “individual” (those commas of course cut both ways). When you’re able to tolerate the loss of up to 90% of your body, it doesn’t pay to have vital organs (like a brain), and would hardly pay to have a low-pain threshold! So, there’s no evolutionary pay-off to feel pain for organisms that can’t “move.” I like to think that if they do, at least they manufacture their own aspirin.

To some though, even talk of emergent properties, smacks of age-old animism: “Plant intelligence’ is a foolish distraction, not a new paradigm … the last serious confrontation between the scientific community and the nuthouse.” Oh Dear! Certainly those of us a little long in the tooth (and with more than our fair share of root fillings) will remember the wilder claims of The Secret Life of Plants in the seventies, and the author’s scrutinising of bananas etc. with a lie detector. The clue was perhaps in the choice of plant. Who knows? To be fair, the same voices limiting such higher order behaviour to animals with brains, are presumably the same cadre reliably informing us, we only imagine we’re experiencing all these things: digging basements, going to the dentist or watching Fawlty Towers. So, are we really that different? Or do we just live in a faster lane to that hard-wooded shoulder? To quote a renowned New-Age crank, Charles Darwin: “(the root tip). . . having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals; the brain being seated within the anterior end of the body, receiving impressions from the sense organs and directing the several movements.” So the root tip is like the head, and as we all know, that’s where the pain is – in your head!