PROTECTING WISCONSIN'S BIODIVERSITY

 
 
   
 
Scientific Name Common Name Global Rank State Rank Federal Status WI Status

Pitcher's Thistle (Cirsium pitcheri)

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Photo by Kitty Kohout

 

Counties with Mapped NHI Occurrences

Pitcher's Thistle (Cirsium pitcheri), a Wisconsin and Federally Threatened plant, is found on open sand dunes adjacent to the Great Lakes. Blooming occurs late-June through late-July, fruiting late-July through late-August. The optimal identification period for this species is late-June through late-August.

Cnicus pitcheri

 
 
 

Pitcher's thistle is an erect forb, 0.5-1m tall, with several white to pale pink flower heads. Phyllaries are 2-3cm long and tipped by weak spines. The fruit are sunflower-like seed pods 5-7.5mm in length. Its leaves are long, linear, and deeply lobed, each lobe is up to 8cm long, 7mm wide, and tipped by a weak spine. The stem and lower leaf surfaces are densely covered in short, white hairs while the upper surfaces may have less dense covering.

Blooming occurs late-June through late-July, fruiting late-July through late-August.

Biennial or perennial. The optimal identification period for this species is late-June through August.

Associated species include Ammophila breviligulata, Calamovilfa longifolia ssp magna, Tanacetum huronense, Elymus canadensis, and Solidago simplex.

Pitcher's thistle is found on open sand dunes adjacent to the Great Lakes.

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 and use care with spot spraying.

Avoid any activities that destabilize the dune, including the use of off-road vehicles, removal of native vegetation, and pedestrian recreational overuse.

Species of Greatest Conservation Need (SGCN) are associated with habitats (or natural communities) and places on the landscape. Understanding relationships among SGCN, natural communities and ecological landscapes help us make decisions about issues affecting SGCN and their habitat and how to respond. Download the Wildlife Action Plan association score spreadsheet to explore rare species, natural communities and ecological landscape associations

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the Wisconsin Wildlife Action Plan because lack of information can threaten our ability to successfully preserve and care for natural resources.