[regularfry]

I remember one of my teachers about 35 years ago telling us about a specific fern that concentrated gold in its roots. I can't remember the name of it but I'd recognise it by sight. It was interesting because as an organism it's virtually unchanged in appearance since examples of it were laid down in the coal layers. So it's not an unlikely story at all.

[regularfry]

A flash of memory immediately after hitting reply and a quick google brings me to https://www.sciencedirect.com/science/article/abs/pii/037567... - looks like gold accumulation is a myth, but it tends to accumulate arsenic which can be an indicator for the presence of gold.