The plant article in question can be found here. I was wrong about scientists being puzzled, but it's also possible evidence for a species-specific morphic field.

Populations increasing until strain is put upon resources would seem to be to be simple observable fact. Unless there is something holding numbers back artificially, such as habitat loss or disease, then the population will eventually expand as far as limits allow. This is happening with humans right now and we're going in a direction where we're putting too much pressure on our own natural resources. The availability of things like food and water are natural limiting factors. Can I ask why this seems so ludicrous to you?