The Key Largo tree cactus is no longer found in the US: "I was astonished"

The tropical cactus that was once native to the Florida Keys is now extinct in the United States, except for some conservation collections, according to a field biologist who spoke to Planet Chronicle Digital.

The Key Largo tree cactus was destroyed by rising sea levels and other factors, as stated in a paper published in the Journal of the Botanical Research Institute of Texas by Jennifer Possley.

Possley is the director of regional conservation at Fairchild Tropical Botanical Garden in Coral Gables, Florida, near Miami. She is part of a team of scientists and researchers who have been studying the species since it was first discovered at John Pennekamp Coral Reef State Park in 1992.

"Considering the Key Largo tree cactus was two stories tall and as wide as a few cars, which sounds crazy in some ways," Possley told Planet Chronicle Digital.

""In a remote location surrounded by tall mangroves, it was impossible to miss this isolated area," she stated."

It is uncertain how long the Key Largo tree cactus has been present, but Possley believes it could have been there for over a century.

Many rare plant species in the Florida Keys are threatened by sea-level rise, as stated in the paper.

In 2007, the Key Largo tree cactus, scientifically known as "Pilosocereus millspaughii," was thriving at Florida's state parks, according to Possley. The cactus continued to flourish for several years.

It was clear that "something was eating the cactus."

By 2012, Possley stated that it "began to decline slightly, but nothing concerning."

By 2015, it was evident to Possley and others that "the cactus was being consumed."

She said that the extensive marks and damage on the plant killed a lot of it because her eyes bugged out.

Despite Possley's prediction that it should recover, the cactus declined further due to major hurricanes and "king tides."

We had never seen salt water lapping at the roots of the plants before, as stated by Possley by 2019.

In July 2023, it was clear that the Key Largo tree cactus would not survive, according to Possley.

"The other cacti in the region … are threatened with a similar fate."

The paper stated that the decline and extinction of the species in the region coincided with the increase in sea levels.

"In the Florida Keys, rare plants and other cacti in the region face a similar threat."

But it's unfair to solely blame sea-level rise, Possley clarified.

"Sea-level rise may have contributed to the disappearance of this cactus, according to her," she said.

"The hurricanes and the herbivory were undoubtedly responsible for the damage."

The Key Largo tree cactus may not be the first species lost due to sea-level rise complications, according to Possley.

The Keys contain "several plants" that are "seriously endangered."

""This species, which we could claim as part of our botanical heritage here in South Florida, is now gone," she said."

Despite its disappearance from the U.S. environment, the Key Largo tree cactus is not considered extinct.

The plant lives in coastal areas of Cuba and the Bahamas, as well as in conservation collections, according to Possley.