Key Largo

Shannon, who has flown in from Key Largo, Fla., with his family, is no stranger to the show’s tapings; this is his 16th time attending.

From an initial population of more than 150 stems in the Florida Keys, the once-thriving Key Largo tree cacti began dwindling due to salt water intrusion, soil depletion, intensified hurricanes and unusually high tides, all of which are either caused or exacerbated by global warming.

As a result, the Key Largo tree cactus is now locally extinct from both the Florida Keys and the United States as a whole, though other related cacti are indigenous to Cuba and the Bahamas.

Even worse, the scientists who chronicled the Key Largo tree cactus' extinction are now predicting that this is only foreshadowing future local extinctions as part of the ongoing sixth mass extinction driven by human activity.

As for the Key Largo tree cactus, "This is the first of many losses likely to be suffered in the coming decades," research botanist Jimmy Lange told Salon.