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Dwarf Bilberry (Vaccinium cespitosum)

Life history

Species overview

Dwarf Bilberry (Vaccinium cespitosum), a Wisconsin Endangered plant, is found in pine barren openings and can often be located by searching for the northern blue butterfly whose larvae feed exclusively on this shrub. Blooming occurs late May through late June; fruiting occurs throughout July. The optimal identification period for this species is late May through late August.

Synonyms: Vaccinium arbuscula, Vaccinium cespitosum var. arbuscula, Vaccinium cespitosum var. cespitosum


  • Distinguishing characteristics: Plants mostly 1 to 2 dm, making them smaller than V. angustifolium. The leaves of V. cespitosum are toothed, which can be used to distinguish it from V. uliginosum, a species with similarly small leaves.
  • Flower characteristics: Bell-shaped, solitary in the axils of the lower leaves of the season; sepals very short and broad; corolla 5 mm, usually pink with spurred anthers.
  • Fruit characteristics: Blue, 6 to 8 mm.
  • Leaf characteristics: Deciduous, firm, 1 to 3 cm, obtuse or rounded above, tapering to the base, finely bristled teeth at least in the upper half.


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


  • Growth form: Shrub
  • Vegetative reproduction: Superficial rhizomes
  • Life cycle: Perennial
  • Comments: Associated Species: Pinus banksiana, P. resinosa, Comptonia peregrina, Pteridium aquilinium, Poa compressa, Hieracium aurantiacum, Carex pensylvanica, Vaccinium angustifolium, V. myrtilloides.

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 Dwarf Bilberry (Vaccinium cespitosum). 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 Vaccinium cespitosum in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusEND
Federal Status in Wisconsinnone
State RankS2
Global RankG5
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 pine barren openings and can often be located by searching for the northern blue butterfly whose larvae feed exclusively on this shrub.
  • Soils: Sandy or loamy soils.

Natural communities

This table lists the natural communities that are associated with Dwarf Bilberry. 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 Dwarf Bilberry. 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.

  • Surveys for northern blue butterflies should also be conducted to avoid disturbing populations 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 site preparation that heavily disturbs herbaceous ground layer and soil; these include bulldozing and furrowing, as well as grubbing and stump removal.
  • Avoid locating landings, staging areas, or access routes in open sandy areas dominated by native grasses.
  • 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

  • Maintaining open habitat will benefit V. cespitosum as well as the state endangered northern blue butterfly, which uses V. cespitosum as its larval host. However, invertebrate populations can respond poorly to a temporary loss of habitat, which occurs when using prescribed fire to control woody plant encroachment. If prescribed fire is used a rotation should be set up where some sections of an area are burned and others are left as unburned refugia for populations of vulnerable species. Over the course of time, all sections of an area will be burned although never in the same year.
  • Prescribed burns and/or brushing may be beneficial (dependent on local site conditions).
  • Survey for and control invasive plants prior to conducting timber operations, as these can be spread by vehicles and often respond vigorously to increased light; see forestry BMPs for invasive species.
  • Maintain and restore open habitat through selective clearing and brushing.


Dwarf Bilberry Photo.

Photo © Emmet Judziewicz.

Dwarf Bilberry Photo.

Photo by  staff, Wisconsin DNR.

Dwarf Bilberry Photo.

Photo by Kevin Doyle, Wisconsin DNR.

Dwarf Bilberry Photo.

Photo © Emmet Judziewicz.

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
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