The endangered Lawson cypress occurs naturally only in the valleys of the Klamath Mountains on the borders of Oregon and California. It is a heavyweight among trees, as it can grow to 70 metres tall and 4 metres in diameter. The oldest living specimen is said to be over 1800 years old. The species is now threatened by a fungus, Phytophtora lateralis, which has apparently spread through human agency into the tree’s last outposts. It has no resistance to this fungus, which spreads through the roots, and the infected tree slowly dies.