If it's a high quality brew, it's nearly certainly made with beans from the Arabica species (Coffea arabica), which is known for its finer flavours. Arabica requires a year-round temperature of 59 to 75 degrees Fahrenheit, as well as distinct rainy and dry seasons, in order to grow properly. Comparatively, Adam Moolna writes for the Conversation, Robusta has a harsher taste and is most often used in instant blends.
"As a coffee drinker you don't need to worry in the short term", he said.
A fourth species Coffea eugenoides was bred with Robusta in ancient times to give rise to Arabica, a crossbreed. By better understanding-and being proactive-about the wild species, we may just find ways to brew up a brighter future for the coffee beans we love.
The multi-billion-dollar coffee sector is founded on, and has been sustained through, the use of wild coffee species, researchers said.
Wild Arabica is used to supply seeds for coffee farming and also as a harvested crop in its own right.
All major commercial coffee growing countries have been badly affected by the fungal disease "coffee leaf rust", which spread across Africa and into Asia during the early 20th century, then to South America, becoming entrenched globally by the turn of the millennium.
Coffee is something many of us (including yours truly) can't live without.
"Because if you look at the history of coffee cultivation, we have used wild species to make the coffee crop sustainable".
"A figure of 60% of all coffee species threatened with extinction is extremely high, especially when you compare this to a global estimate of 22% for plants", Dr Eimear Nic Lughadha, a senior research leader at Kew, commented. "There are a broad range of traits, which have good potential for addressing specific issues in the future, whether it's drought tolerance or disease resistance", Davis said.
"Overall, the fact that the extinction risk across all coffee species was so high - almost 60 percent - that's way above normal extinction risk figures for plants", Davis explains. As the researchers note, "Protection of wild populations of Arabica coffee is therefore viewed as a key part of the long‐term sustainability strategy for Ethiopian coffee production and the global coffee sector".
According to researchers, the current efforts to protect wild coffee in biological collections is not enough.
One species, the cafe marron, from the remote island of Rodrigues in the Indian Ocean, was known from only one sighting in 1877.
Where is wild coffee found? It is also being cultured in lab collections at Kew. Genetic diversity is a crucial ingredient for a species' survival in nature.
Sadly, there may be less hope for other species.
What are crop wild relatives?
Furthermore, it was found that 28% of wild coffee species grow outside protected areas and only about half are preserved in seed banks.
Kew's Dr Justin Moat, one of the authors of the paper, said: "These findings are so important as they indicate that the extinction risk to many other coffee species could be much worse if we consider climate change".