Nick Maclaren wrote:
No. The recent outbreak of Dutch elm disease was from timber
with bark on, not plants. Nobody knows what the cause of the
similar decline in paleo/meso/neo-lithic times was.

I have heard, sometimes last year, that they have recently found, 60
years later, a disease coming from the wood which made the american's
soldiers canteen box? This is apparently keeling many trees in Provence
- and spreading.