Marsh grass-of-Parnassus (Parnassia palustris)

Also known as: bog star, grass of Parnassus, grass-of-Parnassus, marsh grass, northern grass of Parnassus, Parnassus
GenusParnassia (1)

The marsh grass-of-parnassus has not yet been assessed by the IUCN.

Named after Mount Parnassus in central Greece, the marsh grass-of-Parnassus (Parnassia palustris) is not in fact a grass, and is rather a member of the family Saxifragaceae (2), which comprises some 580 or so species of flowering plant (3). 

The marsh grass-of-Parnassus can be recognised by its single white, showy flower which stands atop an upright, slender, bald stem. The attractive flower consists of 5 conspicuously-veined petals that are 8 to 13 millimetres in length. The leaves are produced in a rosette at the base of the plant, except for a single leaf on the middle of the flowering stem. The leaves are heart-shaped and taper to the base. The numerous, tiny, oblong seeds are encased in an oval-shaped, four-valved fruit capsule (4).

The marsh grass-of-Parnassus is found across North America, Europe and temperate Asia (4) (5). 

In North America, this species ranges from Alaska east to Labrador, Newfoundland and Quebec, and south to Oregon, Wyoming, North and South Dakota, the Upper Great Lakes region, and New York (4).

The marsh grass-of-Parnassus is most frequently found in alkaline habitats, such as wet moorland, marshes, meadows and high altitude bogs. It may also be found growing on damp calcareous sands on lakeshores (4) (5).

A perennial species, the marsh grass-of-Parnassus flowers in July and August in North America, with the timing of flowering varying elsewhere. Nectar is secreted which aids in attracting insects, including bees, flies and beetles, for pollination (4). However, this species is also capable of self-fertilising if its flowers are not fertilised with the aid of pollinators (5).

The marsh grass-of-Parnassus has an extremely large range and does not appear to be at risk from any major threats. However, some small, isolated populations appear to have low genetic diversity with little connectivity to other populations, increasing their risk of extinction (6) (7).

Although the marsh grass-of-Parnassus has not been the target of any known conservation measures, it occurs in a number of protected areas, including the Isle Royale National Park in the United States (4). 

Where small populations are threatened by low genetic diversity, populations may need to be reconnected by creating suitable habitat between existing areas (7). 

Find out more about the marsh grass-of-Parnassus:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. Catalogue of Life (July, 2011)
  2. Plantlife - Grass-of-Parnassus (July, 2011)
  3. Watson, L. and Dallwitz, M.J. (1992) The Families of Flowering Plants: Descriptions, Illustrations, Identification and Information Retrival. Version 4th March 2011. Universität Hamburg, Germany. Available at:
  4. Michigan Natural Features Inventory - Marsh grass-of-Parnassus (July, 2011)
  5. Plants for a Future - Parnassia palustris (July, 2011)
  6. Bonnin, I. et al. (2002) Population structure of an endangered species living in contrasted habitats: Parnassia palustris (Saxifragaceae). Molecular Ecology, 11: 979-990.
  7. Bossuyt, B. (2007) Genetic rescue in an isolated metapopulation of a naturally fragmented plant species, Parnassia palustris. Conservation Biology, 21: 832-841.