Erigeron maniopotamicus
 Erigeron maniopotamicus is a rare species of flowering plant in the aster family known by the common name Mad River fleabane. It is endemic to northern California where it is known from six occurrences in three disjunct locations in Humboldt and Trinity Counties. It grows in open areas in forest woodland and meadow habitat along the path of the Mad River generally in barren areas without much plant cover.