Plants can recognise their relatives – and even count
If he were that sort of chap, Prince Charles would be within his rights to deliver a right royal ‘I told you so’.
for in the years since he was roundly mocked for saying he talked to plants – and that they ‘responded’ – evidence has grown that he may have been on to something.
And now it appears plants may be smarter than even the Prince of Wales thought.
According to researchers, plants can count, make decisions, recognise their relatives and even remember events. And while they may not have a brain, they can learn in a similar way to humans and animals, say scientists.
Professor Umberto Castiello said: ‘Although the idea that plants may behave in a cognitive way may baffle the public, many of us are genuinely amazed by the complexity of plant responses.
‘Evidence is accumulating supporting notions that plants can communicate, remember, decide, and even count – all abilities that one would normally call cognitive if they were observed in animals.’
Professor Castiello said many studies show their cognitive abilities. one found Venus flytraps can ‘count’ the number of steps their prey made.
Scientists observed that the plant trapped prey only when an insect triggered it twice within 20 seconds. This means the plants can remember the first signal for a short time. The reason why plants need to ‘count’ the steps of its prey could be to avoid wasting energy by responding to random raindrops or windblown debris.
Another experiment showed the flowering plant Mimosa pudica can remember being dropped.
The plant was dropped from 6in 60 times in a row and by the end of the experiment it no longer folded its leaves in a defensive response as it realised being dropped from that height would not hurt.
‘The plant “realises” that being dropped is normal,’ Professor Castiello, from the University of Padua in Italy, wrote. ‘ More astonishingly, this reflex lasts up to a month which demonstrates the acquisition and expression of a long-lasting memory.’
And shrubs can recognise their kin too as they release more chemicals when planted near their relatives which helps them stave off predators.
It is even thought plants can manipulate competitors when resources are scarce. Plants experiencing a lack of water can share this information with nearby shrubs by sending signals via their roots.
This prompts a nearby plant – its competitor – to start conserving water and this behaviour ultimately benefits both.
Professor Castiello concluded: ‘The question should no longer be if plants are cognitive organisms but how plants make use of their cognitive capacities.’
‘Amazed by their complexity’