PROTECTING WISCONSIN'S BIODIVERSITY

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

Swan Sedge (Carex swanii)

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Photo by Ryan O'Connor

 

Counties with Mapped NHI Occurrences

Swan Sedge (Carex swanii), a Wisconsin Special Concern plant, is found most often in oak savannas and open, sandy oak woodlands, as well as in southern mesic forests. It is sometimes reported at moist margins where these habitats transition to shrub-carr. Blooming occurs late-May through early-June, fruiting throughout June. The optimal identification period for this species is throughout June.

Carex virescens var. swanii

 
 
 

Swan sedge is a graminoid, 0.5-1m tall, with distant basal lateral spikes and pistillate terminal spike. At least half the flowers are female, staminate at the base. Perigynia are ascending, obscurely 5-13-veined, obovate-circular, trigonous in cross section, and densely pilose. Beak is absent. Leaf blades are pubescent and longer than the culm, ligules are longer than wide. Pistillate scales are ovate, apex is acute to acuminate, awn is as long as perigynia. Staminate scales are ovate, apex is obtuse or acuminate.

Rhizomatous. Blooming occurs late-May through early-June, fruiting throughout June.

Perennial. The optimal identification period for this species is throughout June.

Associated species include Quercus velutina, Schizachyrium scoparium, Liatris aspera, Prunus virginiana, Tradescantia ohioensis, Potentilla simplex, and Lechea minor.

Swan sedge is most often found in oak savannas and open, sandy oak woodlands, as well as in southern mesic forests. It is sometimes reported at moist margins where these habitats transition to shrub-carr.

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.

Prescribed burns and/or brushing may be beneficial, dependent on local site conditions and burn frequency. Rotational burns with annual unburned refugia may be preferred.

Minimize disturbance to hydrology, including soil disturbance from rutting.

Maintain and restore open habitat through selective clearing and brushing.

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.