Ancient Clones

Illustration of a post card with a photo of a petrified redwood trio at the bottom of a hill and a wayside sign in the left foreground. The words "wish you were here" are written in red on the top left corner. — The famous fossilized redwood trio! See it only at Florissant Fossil Beds National Monument!
NPS/SIP: Mariah Slovacek

This “family circle” of fossilized redwood stumps grew out of the single trunk of an older parent tree. The tree trunks are ancient clones, or genetically identical copies of that parent tree. Modern coastal redwoods also reproduce by stump sprouting. If a redwood is toppled or burned, a ring of new trees often sprouts from burls around the trunk’s base. In the coastal redwood forests, family groups are common. But this trio of stone stumps is unique in the world’s fossil record.

A world map with black continents, a band of green runs through the middle all the way across the Northern Hemisphere.

Redwoods Were Once Widespread

Most people would consider the sight of a coastal redwood forest as a special event! In the Eocene when the Florissant redwoods were growing, redwood tree species were common around the globe. The band of green on this map shows where the trees were growing. This map was developed by the analysis of fossil foliage, wood, and pollen.

A black and white image of a man standing in front of a trio of living redwood trees. — Harry D. MacGinitie standing in front of a modern redwood trio in California.
Courtesy of Carnegie Institution of Washington

Harry D. MacGinitie, shown standing by a modern redwood trio in California, was a paleobotanist who excavated fossils at Florissant in 1936 and 1937. His published work remains the most comprehensive study on Florissant’s fossil plants. MacGinitie was the first to compare these fossils with modern forests in order to reconstruct past climate, ecology, and elevation. The fossil remains of Sequoia are very common fossils at the Monument, including wood, pollen, cones, and foilage.

A single redwood stump grows root sprouts that become three mid-sized redwood trees that slowly engulf the original stump as they become three full grown redwoods, the trees then fade away to the petrified trio stump. — This shows how the fossil redwood trio came about. A singular redwood after being broken or burned sprouted new stems from the roots that grew into three new tree clones. These new trees had their bases buried by a volcanic lahar and were fossilized while the tops of the trees rotted away.
NPS/SIP: Mariah Slovacek

How a Family Circle Forms

If the main trunk of a redwood is damaged, the dormant stems begin growing rapidly, using the parent tree's root system for nourishment and support. Not all the stems manage to grow into a mature tree, and in this case, three grew into a family that was petrified when a lahar covered their bases.