Illegal poaching is the number-one threat to cactus species in Arizona and around the world, according to Dr. Kimberlie McCue with the Desert Botanical Garden.
"There is a black market for cactus just like there's a black market for orchids," she told ABC15.
Of the approximately 1,800 species of cactus, one third are considered endangered. McCue said poachers usually fit one of two categories: landscapers attempting to skirt state law to maximize profits or international collectors that can sell rare cactus species for "tens of thousands (of dollars)" overseas.
"There's a high premium put on cactus that are taken from the wild," she said.
"Depending on the size of the cactus, they'll stuff them in their socks, they'll put them in their pants pocket" to bypass airport security or border checkpoints, she says.
The Desert Botanical Garden is a designated "plant rescue center." Through an agreement with the U.S. Department of Agriculture, cactus seized at government checkpoints are tagged as evidence and sent to the garden to be cared for.
"If the country of origin wants them to be repatriated, we would send them back to that country," McCue said.
How can you help stop cactus poachers?
If you see someone acting suspicious, McCue said you should report it to the state agriculture department. When looking to landscape your property, "know the source of your plants."
It is a felony under Arizona law to cut down or move a cactus without proper authorization.
Saguaro cactuses moved legally are marked with designation tags.