Vanessa Handley, Director of Collections & Research

Here at the Garden, dead plants are generally not cause for excitement. But the fossilized remains of a plant that lived – and died – millions of year ago certainly are. We are therefore delighted to announce the incorporation of our newest (and oldest!) accession: a petrified tree trunk from the Petrified Forest in Northern Arizona. This massive log weighs over 5500 pounds and is now on display at the top of the road to the Tropical House. This magnificent specimen was donated to the Garden by the Oakland Museum of California where it was in collection for many decades.

One end of the log has been cut and polished to reveal the intricate quartz structures within. These resulted from a process of petrification that began during the Triassic (roughly 200 million years ago) during which minerals slowly replaced organic materials inside an ancient tree. This created a durable remnant of otherwise ephemeral tissues, essentially turning the tree into stone. While the identity of our ancient tree is subject to academic debate, it is widely accepted that the Petrified Forest is composed of gymnosperms that blanketed much of North America in dense tropical forest.

By situating the log in close proximity to the Tropical House, we hope to create a fun interpretation point for our visitors. While the composition of tropical lowlands in the Triassic was very different from that of the extant tropics, a visit to our adjacent greenhouse still gives visitors of a sense of the remarkably different paleoclimate of Arizona. We hope you will stop and enjoy the “Pet Log” on your next visit to the Garden!

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