Hemileia vastatrix

Hemileia vastatrix is a basidiomycete fungus in the order Pucciniales and an obligate parasite that can only complete its life cycle on coffee plants. It causes coffee leaf rust, a disease that covers leaves with orange brown fungal spores and causes premature leaf drop, reducing the plant's photosynthetic capacity and lowering both the yield and quality of the harvested beans, with the widely grown species Coffea arabica especially susceptible. First documented in East Africa in the 1860s, the fungus later devastated Sri Lanka's coffee industry in the late nineteenth century so severely that it helped push British consumers toward tea instead. A resurgence across Latin America and the Caribbean between 2012 and 2014 caused roughly one billion dollars in damage and affected more than two million people, and worldwide the disease is estimated to reduce coffee yields by about fifteen percent on average, with regional losses ranging from fifteen to eighty percent. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/