Pedicularis furbishiae, or Furbish's lousewort, is a perennial herb found only on the shores of the upper Saint John River in Maine and New Brunswick.

[3] It is considered an endangered species in the United States and Canada, and is threatened by habitat destruction, as well as riverside development, forestry, littering and recreational use of the riverbank.

Usually after three years the lousewort begins to flower, often from a single, slightly hairy and reddish tinged stem with a few branches near the top.

In this way, it is typical of an entire group of shoreline species (e.g. Sabatia kennedyana, Platanthera flava) that grow in wet meadows created by spring flooding and ice scour, combined with summer low water periods.

[13] It was later discovered in the Saint John River Valley in New Brunswick by Dr. George Stirrett and Frederick Wallace Tribe, prompting the Canadian government to recognize its endangered status in 1980.