In article , lid
says...

About 3 months ago I asked if anyone could identify some seeds which had
mysteriously appeared on the patio. A photo of them can be seen he
https://postimg.org/image/9kkv4lyjx/
(NB original photo link has expired)

I potted a few up and they germinated. The first true leaves have now
appeared, and it was easy to ID the plant.

AAAAAAAAAARGH!!!!! It's ivy.

LOL. Such is gardening :-) I bet we've all nurtured a few cuckoos
until the horrible truth dawned.

Janet.