Xylem’s the green world’s Grand Trunk Road,
the fibre super-highway piping sap
from unlit depots up through bole
to tree-top termini. Plants stretch up tall
to make a thoroughfare.
And yet there’s not a whisper to be heard.
No resonance or rushing in the tubes,
or gurgling in the long capillaries,
or tremolo as sap threads through
the narrowest branches.
Out of foliage pour endless molecules.
The air is thick with them but there is still no sound.
Xylem conceals great silences like that of lymph
or other noiseless interstitial fluids, or corpuscles,
or the unheard motion of bacteria.
– David Morphet 2007