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Bog Bluegrass (Poa paludigena)

Life history

Species overview

Bog Bluegrass (Poa paludigena), a Wisconsin Special Concern plant, is found in forested seeps and fens, mostly under hardwoods and alders. Blooming occurs throughout June; fruiting occurs late June through early July. The optimal identification period for this species is throughout June.

Synonyms: None


  • Distinguishing characteristics: Can be distinguished from other Poa species by its lemmas, which are pubescent on the margins but glabrous between the inconspicuous veins.
  • Flower characteristics: Panicle loose and open, mostly 5 to 10 cm long, the branches long and slender, distant, the lower mostly in twos, spikelet-bearing above the middle; spikelets mostly 4 to 5 mm long, narrow, 2- to 5-flowered.
  • Fruit characteristics: Lemmas 2.5 to 3.5 mm long, webbed at base with a few long hairs, the keel and lateral nerves pubescent on the lower half or two-thirds, the intermediate nerves glabrous, obscure.
  • Leaf characteristics: Sheaths minutely scabrous; ligule short, truncate, the uppermost as much as 1.5 mm long; blades rather lax, mostly erect, .3 to 2 mm wide.


  • Blooming phenology: throughout June
  • Fruiting phenology: late June through early July
  • Optimum time to identify: The optimal identification period for this species is throughout June


  • Growth form: Graminoid
  • Vegetative reproduction:
  • Life cycle: Perennial
  • Comments: Associated Species: Alnus rugosa, Fraxinus nigra, Betula alleghaniensis, Symplocarpus foetidus, Carex bromoides, C. leptalea, C. stipata, Caltha palustris, Angelica atropurpurea, Impatiens capensis, Floerkea proserpinacoides, Tilia americana.

State status

Note: Bog Bluegrass (Poa paludigena) was removed from the Wisconsin E/T list on January 1, 2014 per administrative rule ER-27-11. Learn more.

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 Bog Bluegrass (Poa paludigena). 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.

Documented locations of Poa paludigena in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS3
Global RankG3G4
Tracked by NHIY

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 in forested seeps and fens, mostly under hardwoods and alders.
  • Soils: Moist to wet soils.

Natural communities

This table lists the natural communities that are associated with Bog Bluegrass. 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).

Natural communities score
Northern Hardwood Swamp 3
Shrub Carr 2

Ecological landscapes

This table lists the ecological landscape association scores for Bog Bluegrass. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

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 broadcast spraying of herbicides; use care with spot spraying.
  • 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 direct disturbance to sensitive microsites such as seeps, cliffs, and moss-covered boulders.

Management guidance

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

  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • Follow BMPs, especially around streams and use care near ravines, steep slopes, cliffs, rock outcrops, etc.
  • Buffer management around unique microhabitats such as ephemeral ponds, seeps, etc.
  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.


Bog Bluegrass Photo.

Photo © Barbara Delaney.

Bog Bluegrass Photo.

Photo © Barbara Delaney.

Bog Bluegrass Photo.

Photo © Barbara Delaney.

Bog Bluegrass Photo.

Photo © Barbara Delaney.

Bog Bluegrass Photo.

Photo © Barbara Delaney.

Support for Wisconsin's rare plant information has been provided by the Division of Forestry, the Endangered Resources Fund and the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Wednesday, May 05, 2021
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition