Japanese Stiltgrass
Identification
Appearance
Microstegium vimineum is a delicate, sprawling, annual grass that is 0.5-3.5 feet in height. The stems can root at the nodes.
Foliage
The leaves are pale-green, alternate, lance-shaped, 1-3 inches long, asymmetrical with a shiny, off-center midrib. Upper and lower leaf surface is slightly pubescent. A silvery line runs down the center of the blade. Stems usually droop.
Flowers
Flowering begins in September, when delicate flower stalks develop in the axils of the leaves or at the top of the stems.
Fruit
Fruit is produced from late September through early October.
***Check out the downloadable fact sheet above***
Biology
Ecological Threat
When Japanese stilt grass invades a site, it can quickly crowd out native plant species. Invasions can also change soil nutrient cycling processes, inhibit tree survival and growth, and reduce light availability. After it dies back in late fall, it forms a thick layer of smothering thatch that is slow to decompose. Because stilt grass is relatively unpalatable, it may encourage heavier deer browsing on native plant species.
Origin
Japanese stilt grass was first documented in Tennessee in 1919. Its introduction into the United States was accidental, likely a result of its use as a packing material for porcelain.
Habitat
Forests, forest edges, floodplains, marshes, meadows, fields, riverbanks, lake shore, disturbed areas
Life Cycle
Stilt grass reproduces exclusively by seed. One plant may produce 100 to 1,000 seeds that typically fall close to the parent plant. Seeds may be carried by water during heavy rains or move about in contaminated hay, soil or mud stuck in footwear. Stilt grass seeds remain viable in the soil for five or more years and germinate readily.
Vermont Distribution
iNaturalist project: Mapping for Healthy Forests Vermont
Presumed Present (photographic confirmation, no official voucher)
Citations
PHOTO CREDITS
Japanese stiltgrass, 2308019, David J. Moorhead, University of Georgia, CC Non-com 3.0
Japanese stiltgrass infestation, 1378045, Chris Evans, University of Illinois, CC Non-com 3.0
Japanese stiltgrass against ruler, 5437496, Bruce Ackley, The Ohio State University, CC 3.0
Native White Cutgrass, 5476846, Chris Evans, University of Illinois, CC Non-com 3.0
Native White Cutgrass, 5476845, Chris Evans, University of Illinois, CC Non-com 3.0
INFORMATION CREDIT
Invasive.org, Japanese stiltgrass
Pennsylvania DCNR, Japanese stiltgrass
Vermont Chapter of The Nature Conservancy