The picture, above, is of a clonal grove of quaking aspen in Utah's Fishlake National Forest. Technically, this is one tree.
The grove, called "Pando" from the Latin word for spreading, is among the oldest organisms on Earth, at an estimated 80,000 years. Over 47,000 trunks and stems cover more than 105 acres and weigh an estimated 13 million pounds.
Clonal aspens aren't very good at regular reproduction because they have three sets of chromosomes instead of the usual two.
Aside from fire, the biggest threat to this grove is from deer which eat almost all of the young shoots.