Parnassia palustris
Marsh grass-of-parnassus
Image of Parnassia palustris

Photo by Emmet J. Judziewicz 

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Key Characteristics

Small forb (10-40 cm) of lakeshores and fen and bog mats in the Upper Peninsula; leaves almost all basal, long-petioled, with small rounded, heart-shaped blades (1-3 cm); flowers white with five veined petals, each about 1 cm long.

Status and Rank

  • State Status: T - Threatened (legally protected)
  • State Rank: S2 - Imperiled
  • Global Rank: G5 - Secure


County NameNumber of OccurrencesYear Last Observed
Distribution map for Parnassia palustris

Updated 2/25/2015. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


Marsh grass-of-parnassus is found in a variety of at least somewhat mineral-rich wetland habitats such as fen mats and damp calcareous sands or cobble on lakeshores in the Upper Peninsula.

Natural Community Types


For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Feel free to send questions and comments to Brad Slaughter at

Associated Plants

Sweet gale, bog buckbean, marsh cinquefoil, pitcher-plant, sundew, and leatherleaf.


This plant requires the protection hydrology and its wetland habitat.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Nov 29, 2015]

More Information

See MNFI Species Abstract


Survey References

Technical References