PROTECTING WISCONSIN'S BIODIVERSITY

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

Grassleaf Rush (Juncus marginatus)

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Photo by Karen A. Rawlins

 

Counties with Mapped NHI Occurrences

Grassleaf Rush (Juncus marginatus), a Wisconsin Special Concern plant, is found in acid peaty ditches and depressions in pine and oak barrens. Blooming occurs early-July through early-August, fruiting throughout August. The optimal identification period for this species is early-July through early-August.

Juncus biflorus, Juncus marginatus var. biflorus, Juncus marginatus var. odoratus, Juncus marginatus var. setosus, Juncus setosus

 
 
 

Grassleaf rush is a graminoid, 20-50cm tall. Its stems grow in dense tufts, its bulbous is thickened at the base. Its flowers are subtended by paired bracteoles, petals 2.3-3.3mm, oblong with broadly thin, dry margins, 3 stamens, nearly as long as the tepals. reddish-brown anthers that are much shorter than the filaments, usually soon shriveling. Fruits are incompletely 3-locular, the partitions not meeting in the center, somewhat turgid-inflated, 1.8-2.9mm long and nearly as thick. Principle blades are flat to involute, 1-3mm wide, with 2-3 prominent veins, lacking hard cross-partitions. Leaf sheaths have small, rounded, thin-dry, ear-shaped appendages. Plants are mostly 20-50cm tall, with 15-20 heads. Stems are densely cespitose, bulbous-thickened at the base.

Its height of 20-50cm, 15-20 heads, 1-3mm-wide main leaf blades that are flat to involute, and lack hard cross partitions, along with its densely cespitose stems with bulbous thickened at the base are among its distinguishing characteristics.

Blooming occurs early-July through early-August, fruiting throughout August.

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

Associated species include Pinus banksiana, Viola lanceolata, Rhynchospora capitellata, Muhlenbergia uniflora, Calopogon tuberosus, Juncus canadensis, and J brevicaudatus.

Grassleaf rush is found in acid peaty ditches and depressions in pine and oak barrens.

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

Avoid locating landings, staging areas, or access routes in open sandy areas dominated by native grasses.

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.

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.