PROTECTING WISCONSIN'S BIODIVERSITY

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

Square-stem Spike-rush (Eleocharis quadrangulata)

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Photo by Paul Skawinski

 

Counties with Mapped NHI Occurrences

Square-stem Spike-rush (Eleocharis quadrangulata), a Wisconsin Endangered plant, is found in fen-like sandy lakeshore sedge meadows. Blooming occurs early-June through early-October, fruiting early-August through mid-October. The optimal identification period for this species is late-May through early-October.

Eleocharis quadrangulata var. crassior, Scirpus quadrangulatus

 
 
 

Square-stem spike-rush is an emergent aquatic graminoid, up to 1m tall, with quadrangular stems. Its with cylindric spikelets, 2-5cm long and about as thick as the stem. Its sepals and petals are reduced to bristles, style 2- or 3-parted. Its brown achenes are rounded on sides and 2-3mm long. Tubercles are dark brown and a flattened cone-shape. Stems are stout, sharply 4-angled, up to 1m long and 2-5mm wide. It is a medium to large, clumped spike-rush with brown, oval to obovate scales in 4 rows, 5-6mm long, with chaffy margins.

Its quadrangular stem distinguishes it from similar species.

Rhizomatous. Blooming occurs early-June through early-October, fruiting early-August through early-October.

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

Square-stem spike-rush prefers wet, sandy or calcareous soils and is found in fen-like sandy lakeshore sedge meadows.

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.

Minimize disturbance to hydrology, including soil disturbance from rutting.

Maintain and restore open habitat through selective clearing and brushing.

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.

This species is likely sensitive to water quality. Following BMPs around streams and buffering associated drainages will reduce eutrophication and prevent water quality degradation.

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.