Trees trade genetic information by accidental grafting.

Birch (on left) and Oak (on right) self-grafted

 

 

Scientists were surprised to find unrelated trees in the same forest had nearly identical genetics in their green energy system.  Chloroplasts that harness sunlight are found in green plant matter. They seem to be derived from a domesticated bacteria which has been passed on in the trees' genetic information for millions of years. Trees that grow up crushingly close can have direct tissue contact with unrelated trees, becoming grafted. Some chloroplasts cross over and survive even though the tree's other reproductive information isn't adopted.