Marsh Fleawort
Tephroseris palustris
Tephroseris palustris, also known by its common names swamp ragwort, northern swamp groundsel, marsh fleabane, marsh fleawort, clustered marsh ragwort and mastodon flower, a herbaceous species of the family Asteraceae. It can be seen most easily when its bright yellow umbel flowers appear from May to early July standing 3 to 4 feet along marshes, stream banks and slough areas where it likes to grow.
Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Tephroseris_palustris
Taxonomy & Classification
Kingdom
Plantae
Phylum
Tracheophyta
Class
Magnoliopsida
Order
Asterales
Family
Asteraceae
Genus
Tephroseris
Marsh Fleawort belongs to the family Asteraceae, order Asterales, within the Magnoliopsida class.
Species Profile
Tephroseris palustris, also known by its common names swamp ragwort, northern swamp groundsel, marsh fleabane, marsh fleawort, clustered marsh ragwort and mastodon flower, a herbaceous species of the family Asteraceae. It can be seen most easily when its bright yellow umbel flowers appear from May to early July standing 3 to 4 feet along marshes, stream banks and slough areas where it likes to grow.
Marsh Fleawort faces severe decline primarily due to habitat loss and degradation of its specialized wetland environments. Agricultural intensification, drainage of marshlands, and changes in water management have eliminated much of its suitable habitat across its limited range. The species' highly specific ecological requirements make it particularly vulnerable to environmental changes and human disturbance.
Key Facts
Habitat & Distribution
Tephroseris palustris grows in areas that have freezing winters and in moist to wet soils, such as damp meadows, swamps, sandy pond edges at altitudes of 0 to :America ::North America: Alaska, Iowa, Michigan, Minnesota, North Dakota, South Dakota, Wisconsin, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, Prince Edward Island, Newfoundland and...
Threats
IUCN Red List: Critically Endangered
Marsh Fleawort faces severe decline primarily due to habitat loss and degradation of its specialized wetland environments. Agricultural intensification, drainage of marshlands, and changes in water management have eliminated much of its suitable habitat across its limited range. The species' highly specific ecological requirements make it particularly vulnerable to environmental changes and human disturbance.
Agricultural intensification and land conversion
Drainage and water management changes
Habitat loss and fragmentation
Climate change affecting wetland hydrology
Eutrophication from agricultural runoff
Community Sightings
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Sources & Attribution
How to Cite
IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS
GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org
This page: SpeciesRadar (2025). Marsh Fleawort (Tephroseris palustris). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/marsh-fleawort