PROTECTING WISCONSIN'S BIODIVERSITY

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

Dwarf Lake Iris (Iris lacustris)

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Photo by Len Place

 

Counties with Mapped NHI Occurrences

Dwarf Lake Iris (Iris lacustris), a Wisconsin and Federally Threatened plant, is found near Lake Michigan on beach ridges, stabilized dunes, limestone ridges, forest gaps and edges, and ditches. Blooming occurs early-May through early-July, fruiting late-June through late-July. The optimal identification period for this species is late-May through early-July.

Iris cristata ssp. lacustris, Iris cristata var. lacustris

 
 
 

Dwarf lake iris is an erect forb, 5-15cm tall, with violet flowers 5-6cm wide and a dull yellow perianth tube, 1-2cm, dilated upwards, and shorter than the sepals and petals, which are notched at the apex. Seeds are dark brown with an aril (fleshy thickening of seed coat). Leaves are broadly linear, with curved-arching, 4-6cm at anthesis, later 15cm long by 5-10mm wide.

Plants are much shorter in stature (less then 15cm vs 50-100cm) than other Iris species in our region.

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

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

Associated species include Thuja occidentalis, Abies balsamea, Zigadenus glaucus, Carex eburnea, Cornus canadensis, Juniperus communis, Shepherdia canadensis, Polygala pauciflora, and Arctostaphylos uva-ursi.

Dwarf lake iris prefers gravelly, calcareous soils and is found near Lake Michigan on beach ridges, stabilized dunes, limestone ridges, forest gaps and edges, and ditches.

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.

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

Maintain partial canopy to encourage woodland species, avoid closed-canopy 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.

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.