While waiting at a bus stop next to the Arbutus Greenway - an old railway line - I noticed some leaves that seemed out of place amongst the bramble. Upon closer inspection, it turned out to be from a grape vine which I assume had grown from seed from a passerby. It had managed to intermingle with the blackberry, climb some 20-30' up a nearby tree, and produce fruit in doing so. I have to applaud its tenacity. I've seen wild apple trees before but not a grape vine. What plants have you seen in an unexpected place?
I am always surprised and delighted to see new plants growing where ants have taken seeds. Myrmecochory - AntWiki Whenever you see trilliums, hellebores, cyclamens, bleeding hearts, gingers, etc. growing in unexpected places, it could very well be ants who have taken the seeds there. The most recent I have discovered just this year is autumn flowering crocus (Colchicum autumnale) cropping up and blooming in a number of locations far from where the corms were first planted (and long-since removed).