What does it mean to be a tree? Undead stumps and albino redwoods.

This is a fascinating article about how some stumps are stay alive by grafting their roots to other trees. In exchange for the energy derived from other trees, they provide water siphoned up at night when the other trees aren’t active. It’s not clear if the grafting happened before or after the tree was cut down.

“If lateral water transport between trees proves to be a common phenomenon, we have to rethink our definition of a ‘tree’,” said Leuzinger. “In fact, we may be looking at the forests as superorganisms that redistribute water between genetically different individuals.”Undead Tree Stump Is Being Kept Alive by Neighboring Trees

There’s another example of this described in this article. Redwoods that can’t photosynthesize their own nutrients, but get their nutrients from other trees, and in return seem to help process toxins.

“The albino is a parasitic growth, unable to photosynthesize its own nutrients and entirely reliant on its host or sibling tree for sustenance through the fantastic network of roots beneath our feet,” he says. “Scientists don’t really understand why albino redwoods exist. Some believe they may help the host tree process toxins or heavy metals.”The Ghosts Of The Redwood Coast