One tree has 47,000 trunks and weighs 6,000 tonnes

In Fishlake National Forest, in southern Utah, 47,000 quaking aspens grow that are not 47,000 trees: they are one. Every trunk rises from the same root network and carries the same DNA, so botany counts them as a single individual. It is called Pando — Latin for "I spread" — and it covers 43 hectares, about sixty football pitches.

What we call trunks are stems the root pushes up and lets go. The whole organism weighs some 6,000 tonnes, which makes it the heaviest living thing ever measured: a blue whale, the largest animal on the planet, comes in around 150.

Pando is male and all its stems are clones, so it does not reproduce by seed: it grows by stretching root. Its age is disputed, because a root leaves no rings to count.

What is known with numbers is how it is dying. Deer and elk devour the new shoots the moment they appear, so the root keeps pushing stems and almost none reaches adulthood. Since 2013 the forest service has been fencing off plots to keep the animals out: inside the fence the shoots get past a hand's height and thicken; outside, they are eaten before they lift their heads.