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September 5, 2015
Jennifer Hillmer
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Japanese stiltgrass (Microstegium vimineum)

Posted in Species Profiles

Microstegium infestation_Mehrhoff

 Description:

Japanese stiltgrass is an annual grass reaching heights of up to 4 feet and resembling a small, delicate bamboo. Narrow lance shaped leaves have a silvery stripe of fine hairs along the midrib of the upper leaf surface.  Flower spikes appear in September.

microstegium_1 Microstegium seeds _Hurst

Habitat:

Japanese stiltgrass grows in various environments including moist open woods, wetlands, uplands, fields, thickets, roadsides, and ditches. This grass thrives in areas subject to disturbance. It prefers acidic to neutral soil high in nitrogen.

 

Invasive Traits:

Japanese stiltgrass is well adapted to low light conditions and forms dense lawns in areas where it grows vigorously. It will shade and crowd out native vegetation. Seeds are dispersed by wind and foot traffic and will remain viable in the seedbank for 5 years.

Picture of heavy thatch of dead stiltgrass.
Stiltgrass is still visible in winter as sprawling patches of leaf litter.

Control:

Manual pulling is effective on isolated populations only when roots are removed and remains are bagged and transported off site.

Picture of a young Japanese stiltgrass plant.
This annual grass can be pulled or sprayed with herbicide throughout most of the growing season, as long as the plants are not setting seed.

 

Picture of stiltgrass leaf and stems showing smooth nodes.
The silvery midrib and smooth nodes on stiltgrass stems are key traits which differ from the native whitegrass (Leersia virginica).
Picture of stiltgrass stem and roots.
Mature plants have a sprawling habit, with stilt-like roots forming along the stem.
5483593-PPT
The key diagnostic for stiltgrass is the reflective stripe of hairs along the midrib. This shine, plus the smooth nodes along the stem, are key to distinguishing it from whitegrass (Leersia virginica), a native grass.
Further Reading

Gover et al. 2008

Swearingen & Adams 2008

Photo credits
  1. Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
  2. Cleveland Metroparks
  3. Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org
  4. Chris Evans, Illinois Wildlife Action Plan, Bugwood.org
  5. James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
  6. Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
  7. Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
  8. Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Jennifer Hillmer

Jennifer Hillmer

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