Elke Mackenzie was a botanist and polar explorer who scoured arctic landscapes for lichen during the mid-twentieth century. Her exhaustive collection and description of lichen, primarily from the Stereocaulon genus, remains our greatest understanding of lichen from these harsh environments. Throughout her career, Elke curated lichen in herbariums around the world and worked as a professor in Argentina. She served as Director of the Farlow Herbarium at Harvard University for 19 years before retiring in 1972.