> Ultrasonic sounds from plants, plants speaking at 40 kHz to 80 kHz
>>formatting link>
> The plants are not speaking at all. Sounds caused by cavitation effects as internal water columns drain due to dehydration is not speaking.
They might just possibly be communicating with insects - saying words to the effect of "Go away - I'm toxic". But I don't see an obvious mechanism for them to generate such ultrasonic clicks though.
Capillary effects in xylem are strong enough to support very tall columns of water as tall trees demonstrate so well.