Bigtooth Aspen

Bigtooth Aspen
Populus grandidentata

All of the trees in the picture above are possibly one plant.   Several tree species form these clonal groves of trees, including the Aspens, Cottonwoods, Poplar, Pawpaws, Sumac, etc.

They send out lateral roots which occasionally send up a new shoot.  Damage to the root or damage to the parent tree can signal the plant to start growing a new shoot.  It's caused by a complicated interplay of hormones and growth inhibitors.

The Quaking Aspen (Populus tremuloides) does this to a much greater degree than any other species.  In fact, the oldest and heaviest living organism is a grove in Utah that has been determined to be at least 80,000 years old and weighs 6600 tons.  It even has a name, Pando, which is Latin for "I spread".

So, are all of the trees in one of these groves considered a tree, or is the whole thing a tree?

The leaves have big teeth, as compared to Quaking Aspen.