Common Butterwort (Pinguicula vulgaris)

Life history

Species overview

Common Butterwort (Pinguicula vulgaris), a Wisconsin Endangered plant, is found on moist ledges and mossy boulders on shaded sandstone cliffs in the Apostle Islands. Blooming occurs early June through early July; fruiting occurs throughout July. The optimal identification period for this species is late June through late July.

Synonyms: Pinguicula vulgaris var. americana

Identification

• Distinguishing characteristics: Very distinctive. There are no other species of this genus in the state. The flowers may appear similar to a violet although the leaves can be used to distinguish the two genera.
• Flower characteristics: Corolla violet, 1.5 to 2 cm (spur included), 5-lobed, 2-lipped, the lower lip longer than the upper and prolonged into a conspicuous basal spur; calyx 5-lobed, somewhat 2-lipped.
• Fruit characteristics: Capsule small, 4 to 6 mm long, globose; seeds small.
• Leaf characteristics: Basal, commonly 3 to 6, ovate to elliptic, 2 to 5 cm long, very obtuse, narrowed to the base, the upper surface sticky.

Phenology

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

Other

• Growth form: Forb-erect
• Vegetative reproduction:
• Life cycle: Perennial
• Comments: Associated Species: Primula mistassinica, Trisetum spicatum, Agrostis hyemalis, Thuja occidentalis, Sorbus decora, Betula papyrifera, Ledum groenlandicum, Carex capillaris, Alnus crispa, Betula papyrifera. Small insects caught on the slimy leaf surface are digested.

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 Common Butterwort (Pinguicula vulgaris). 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 moist ledges and mossy boulders on shaded sandstone cliffs in the Apostle Islands.
• Soils: Wet soils.

Natural communities

This table lists the natural communities that are associated with Common Butterwort. 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 Common Butterwort. 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 direct disturbance to sensitive microsites such as seeps, cliffs, and moss-covered boulders.
• 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

• Buffer management around unique microhabitats such as ephemeral ponds, seeps, etc.
• 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.

Other resources

Links to additional Common Butterwort information

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

• Wisconsin Flora
• NatureServe Explorer
• 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 Natural Heritage Conservation Program for educational uses. Photo use