Life history

Species overview

Marsh Grass-of-Parnassus (Parnassia palustris), a State Threatened plant, is found on clay bluffs along Lake Superior, and in cold northern fens, and calcareous sand or gravel pits. Blooming occurs early August through early September; fruiting occurs throughout September. The optimal identification period for this species is throughout August.

Synonyms: Parnassia multiseta, Parnassia palustris ssp. Neogaea, Parnassia palustris var. neogaea

Identification

• Distinguishing characteristics: Cauline leaf as large as basal leaves.
• Flower characteristics: Flowers bisexual; petals white, 5- to 17-nerved, 9 to 13 mm, half to twice as long as the lance-triangular, green sepals.
• Fruit characteristics: Numerous oblong, angular seeds.
• Leaf characteristics: Mostly basal with one cauline leaf, entire, palmately veined; blades of basal leaves broadly ovate to almost rotund, 1 to 3 cm, three quarters to fully as wide, broadly rounded or more often cordate at the base; cauline leaf as large as the basal, broadly ovate, sessile and cordate-clasping.

Phenology

• Blooming phenology: early August through early September
• Fruiting phenology: throughout September
• Optimum time to identify: throughout August

Other

• Growth form: Forb-erect
• Vegetative reproduction:
• Life cycle: Perennial
• Comments: Associated Species: Alnus crispa, A. rugosa, Salix spp., Carex lacustris, Typha latifolia, Mimulus glabratus, Juncus brevicaudatus, Solidago canadensis, Equisetum arvense, Fragaria virginiana.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for Marsh Grass-of-Parnassus (Parnassia palustris). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

• Habitat description: Found on clay bluffs along Lake Superior, and in cold northern fens, and calcareous sand or gravel pits.
• Soils: Moist to wet, sandy, gravelly, or calcareous soils.

Natural communities

This table lists the natural communities that are associated with Marsh Grass-of-Parnassus. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Ecological landscapes

This table lists the ecological landscape association scores for Marsh Grass-of-Parnassus. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

• Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.
• Avoid broadcast spraying of herbicides; use care with spot spraying.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

• Follow BMPs, especially around streams and use care near ravines, steep slopes, cliffs, rock outcrops, etc.
• Minimize disturbance to hydrology, including soil disturbance from rutting.
• Maintain and restore open habitat through selective clearing and brushing.

Other resources

Links to additional Marsh Grass-of-Parnassus information

• Michigan Natural Features Inventory [exit DNR]
• NatureServe Explorer information [exit DNR]

Other links related to vascular plants (all exit the DNR website)

• Wisconsin Vascular Plants
• Freckmann Herbarium
• Atlas of Wisconsin Prairie and Savanna Flora - Wisconsin State Herbarium
• USDA - NRCS Plants Database
• USGS Midwestern Wetland Flora - field office guide to plant species
• eFloras
• Cofrin Center for Biodiversity Herbarium
• Intermountain Herbarium Grasses of North America
• Orchids of Wisconsin

Photos

Click to view a larger version. Please considering donating a photo to the Endangered Resources Program for educational uses. Photo use