"Save the animals!" is a well-known rallying cry among animal-rights activists. Those activists may soon be shouting "Save the coffee beans!"  

Despite the discovery of seven new species of wild coffee during a worldwide survey conducted by the Royal Botanic Gardens, botanists worry that three-quarters of the world's wild coffee plants may be endangered.

Two of the newly discovered plants — Coffea ambongensis and Coffea boinensis— have the largest seeds of any wild coffee species, reports the BBC. Those giant beans are more than twice the size of Arabica coffee (Coffea arabica), the main species used in commercial coffee production.

"Coffee is the world's second most traded commodity, after oil, with at least 25 million farming families dependent on its production for their livelihoods," explained RBG Kew's coffee expert Aaron Davis. "Yet, we still have much to learn about its wild relatives."

Dr Davis estimated that almost three-quarters of the world's wild coffee species are threatened as a result of habitat loss and climate change.

"Conserving the genetic diversity within this genus has implications for the sustainability of our daily cup, particularly as coffee plantations are highly susceptible to climate change," he added.

Read more on this story at the BBC.