Erigeron muirii (Muir's fleabane) is a rare Arctic species of flowering plant in the daisy family. It has been found only in northern Alaska and the northern Yukon Territory, including Herschel Island in the Arctic Ocean. It grows in tundra, dry slopes, and rock outcrops. Erigeron muirii was discovered by noted conservationist John Muir near Cape Thompson, Alaska during his travels there in 1881. Muir sent the plants he collected to his friend and botanist Asa Gray, who determined that the Erigeron was a new species, which he named in honor of Muir.