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We're a weekly program. Our job is to add in-depth analysis to one question

from the news. We hope you like it. You're listening to the BBC World Service. This is Helena Merriman with the inquiry.

This week, have we underestimated plants?

A lab in Florence, a line of potted plants hangs just above the floor.

They're mimosa pudicus, better known as the sensitive plant or touch me knots,

because when they're so much as brushed their leaves curl up.

They're set for an experiment which will test a daring hypothesis.

It begins, the plants are dropped to the floor. The small jolt is just enough for their

leaves to curl up. They're raised and dropped again. Again their leaves curl up.

Again and again leaves curl up. Again and again, the experiment produces the same result.

But then, something amazing happens.

After around 60 drops, the sensitive plant appears to be a little less sensitive.

The leaves no longer fold up when the plants hit the ground.

It seems that the plants have realized that the drop causes them no harm,

which is why they're no longer reacting.

The scientists are astonished.

They say the hypothesis was right.

Plants can do something that up till now, no one thought them capable of.

Plants can learn.

It's just one of a number of experiments that have been carried out in the name of plant intelligence.

Those conducting them say that a better understanding of this could help us solve some of the world's thorniest problems in agriculture, climate change, medicine,

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