The tip came from a woman standing in line at a post office in a small town in northern California.
A customer was shipping dozens of boxes to China, and the caller suspected they were filled with abalone, a highly-prized shellfish listed as an endangered species.
But fish and wildlife officers who responded to the call instead uncovered an international smuggling ring that has been stripping the bluffs along the northern California coastline of Dudleya succulent plants and shipping them to countries in Asia where they are used for decoration.
"The poachers literally fly into the US just to get these plants so they can ship them to Korea, China or Japan," said Captain Patrick Foy, of the California Department of Fish and Wildlife. "They are ripping them out of the ground and selling them between $40 and $50 dollars a piece."
The plant, which grows in bud-like circles and resembles an artichoke, is called Dudleya farinosa and is native to the rugged coastlines of Oregon and northern California.
Foy said several suspects from Asia have been arrested in recent months in connection with the heists, including two Koreans and one Chinese national who were nabbed on April 4.
The trio had entered the country as tourists and were detained as they were about to ship 1,334 of the plants overseas. An additional 1,000 Dudleya were later found in their hotel room.
'They favor remote locations'
The three men—Tae Hun Kim, 52, and Tae Hyun Kim, 46, both of North Korea, and Liu Fengxia, 37, of China—are scheduled to appear in a California court on May 16, charged with several felony and misdemeanor counts. If convicted, they face up to nine years in prison and steep fines.
At least two other similar cases are pending.
Foy said he believes poachers in the last year have quietly been slipping into the country, targeting remote areas along the coast and digging up "thousands and thousands" of Dudleya before stuffing them into boxes with crumpled up newspaper and putting them in the mail.
"They go in at night or during the day... and seem to favor locations that are not well traveled—places where you can park your car and walk half a mile and not be seen by a lot of people," he added.
"These are people who are taking every plant that they can find and they are shipping them by the hundreds of boxes at a time."
Authorities said they fear the plant, also known as "bluff lettuce," could end up on the endangered species list if the poaching continues and are warning of the detrimental effect on the environment.
"They are ripping the plants out of their habitats and they are trampling other plants while they are doing it," said botanist Stephen McCabe, emeritus director of research at the University of California Santa Cruz Arboretum.
"It's just disgusting that they are going into the wild and stripping whole cliffs."
The Dudleya, which can continue to grow for years once potted, is said to be highly prized in China because of its resemblance to the lotus flower.
Foy said that while he understands the attraction, he was baffled as to why collectors were not simply buying similar-looking plants.
"Why these ones are so much extra special, frankly I have no idea," he said. "There are perfectly other nice succulent plants out there that can be purchased for five dollars at a nursery."
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