How did Earth's poison plants come to the Predators' hunting planet?
In Predators (2010) when the humans landed on the alien planet, Edwin finds a poisonous plant that grows on Earth. He even knows the scientific name for that, he told it to the others but they didn't listen.
How did these Earth poison plants come to the alien planet?
Did the Predators add them to their hunting planet to get a more interesting hunt?
This is never explained
The implication though is that the Predators have been in contact with Earth for millions of years.
There is a comment in the
They have been extinct since the early Cretaceous period. 125 million years ago.
Humans did not exist 125 million years ago so it's unlikely that the transportation of plants then would have been related to hunting them.
It's possible that the plants were transplanted to make the hunting of other creatures more interesting but there is nothing written about that.