The onion feels when you cut it - but does not hurt.
Now researchers in Lund have found new clues to what happens in the plants when they are touched.
The hope is that the research will lead to more sustainable cultivation methods.
It has been known since Darwin's time that plants react with different mechanisms of contact. A plant that grows on a windy hill becomes shorter and more stable to withstand the wind. If an insect lands on a leaf, the plant can feel it and start a defense.
The onion feels when you cut it - but does not hurt.
Now researchers in Lund have found new clues to what happens in the plants when they are touched.
The hope is that the research will lead to more sustainable cultivation methods.
It has been known since Darwin's time that plants react with different mechanisms of contact. A plant that grows on a windy hill becomes shorter and more stable to withstand the wind. If an insect lands on a leaf, the plant can feel it and start a defense.