A Palmer’s oak (Quercus palmeri) discovered in Southern California is estimated to be over 13,000 years old, making it one of the oldest plants on Earth.
When a team of researchers led by Michael May of the University of California, Davis, first found what appeared to be a thicket of stunted, gnarled oak trees, they noticed that something wasn’t right. First of all, Palmer’s oaks don’t usually grow in the hot, parched climate of Southern California. Further, none of the trees produced fertile acorns, so the plants couldn’t reproduce.
Researchers also noticed that the trees were more similar in appearance than they should be, leading them to think they might be clones of a single plant.
Genetic analysis confirmed their theory: each of the 70 stems were genetically identical. They weren’t a grove of trees; they were clones of the same plant.
The team estimated that the newly discovered oak–now named the Jurupa Oak after the mountains in which it grows–started from a central trunk and grew outward at a rate of one-twentieth of an inch each year, relying on fire to burn down stems and trigger the plant to send out new sprouts. The team’s findings are reported in the online journal PLoS One.