I have ivy that climbs up the wall, over the kitchen window sill, and up the
glass until I cut it back. All fronds grow vertically ove rthe glass except
those within a foot or so of being under an extractor fan mounted in the
glass and used daily. Those fronds grow unerringly directly, diagonally,
towards the extractor.
What evolutionary reason is there for ivy to grow towards a source of
vibration ?
Its the same every year, not some random quirk.