There are 1,480 living species of cacti, all but one indigenous to the Americas. The journal Nature Plants recently studied the level of danger to almost every species on earth––the largest study of any plant taxon––and the alarming result was 31 percent are threatened, the fifth most of any taxonomic group, just behind amphibians and corals. Loss of habitat to humans and the clumsy plodding of livestock factored highly. No surprise. But what shocked the report’s author was that the largest extinction threat comes from horticulture, specifically the illegal collection and trade of cacti. ... Last October, Chinese and German customs agents busted a smuggling ring and seized 1,250 plants, some rare and endangered cacti. As might be expected, there are few scholarly reports investigating the cactus black market. One such report, called “Prickly Trade” (the cactus world is full of egregious puns), estimated that in one three-year period people illegally plucked about 100,000 cacti out of the Texas wild or smuggled them over the Mexican border. That was in 2003. Then Internet commerce arrived. A report from 2012 monitored just 24 online cacti sellers for 1,000 purchases. These were not just any 1,000 cacti. Each was listed as an “Appendix I” specie by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which are plants threatened with extinction. To trade any of these, a seller needs a permit. Of the 1,000 cacti researchers monitored, the report found at least 90 percent had traded hands illegally.