PROTECTING WISCONSIN'S BIODIVERSITY

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

Ram's-head Lady's-slipper (Cypripedium arietinum)

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Photo by Thomas Meyer

 

Counties with Mapped NHI Occurrences

Ram's-head Lady's-slipper (Cypripedium arietinum), a Wisconsin Threatened plant, is found in two habitats, cool, dense, calcareous conifer swamps and cool, sandy margins of conifer forests, boreal forests, and dunes. Blooming occurs late-May through early-June, fruiting late-June through late-July. The optimal identification period for this species is late-May through early-June.

 
 
 

Ram's-head lady's-slipper is an erect forb, 10-40cm tall, with a slender, thinly hairy stem that has 2-3 sheathing scales below and 3-5 sessile leaves above the middle. It has a solitary, strongly reddish-purple-veined flower with a 1.5-2.5cm long pouch with a white lip. Its lateral sepals are thin, linear, greenish-brown, separated to base. Its dorsal sepal is 12-25mm long and 5-13mm wide. Its fruit is a capsule with tiny seeds. It has 3-5 leaves that are spiraled around stem, sessile, 5-10cm long, lance-shaped to elliptic, and may be finely pubescent, and occasionally folded.

Cypripedium arietinum may be distinguished from other Cypripedium species by the arrangement of its leaves, which are spiraled rather than 2-ranked. Its flower head is quite distinctive as well and cannot be confused with any other species.

Blooming occurs late-May through early-June, fruiting late-June through late-July.

Perennial. The optimal identification period for this species is late-May through early-June.

Associated species include Thuja occidentalis, Abies balsamea, Picea glauca, Betula papyrifera, Shepherdia canadensis, Cypripedium parviflorum, C reginae, Coptis trifolia, Cornus canadensis, and Carex eburnea.

Ram's-head Lady's-slipper prefers cool, sub-acidic to neutral soils and is found in two different habitats, one is cool, dense, calcareous conifer swamps and the other is cool, sandy margins of conifer forests, boreal forests, and dunes.

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 locating landings, staging areas, or access routes on or near known populations.

Avoid broadcast spraying of herbicides and use care with spot spraying.

Avoid site preparation that heavily disturbs herbaceous ground layer and soil, including bulldozing and furrowing, as well as grubbing and stump removal.

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

Minimize disturbance to hydrology, including soil disturbance from rutting.

Avoid rapid and dramatic reductions in canopy cover and, basal area, in wet areas to reduce risk of swamping.

Although maintaining high overall forest canopy is important, silvicultural techniques that open small gaps in the canopy may be beneficial to this species. Seedlings and saplings of some species in openings may need to be protected from deer browse.

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.