"Shut up and die," the orchid's flower tells its petals once it is pollinated. But the language used is not known to us - it is chemical talk and in orchids, ethylene does the talking. Now, botanists have found a way of tapping into the chemical talk of plants using lasers which are so sensitive as to pick up even one molecule of the substance targeted. A lot of work has been done with lasers tuned in to ethylene gas - a plant hormone, which can be released if the plant is overwatered (BBC- Wildlife, Vol 13, No 5).

Lately, Bristol University botanists have been targeting a fragrant gas called methyl jasmonate that appears to warn neighbouring plants of potential insect attacks.