Japanese stiltgrass, Nepalese browntop
Microstegium vimineum (Trin.) Camus

SOURCE: The following information on this species is taken, in part, from the Plant Conservation Alliance, Alien Plant Working Group, Weeds Gone Wild website, Fact Sheets. The Fact Sheet information for this species can be found at http://www.nps.gov/plants/alien/factmain.htm. Modifications include additional pictures (from www.invasives.org) and resource information. Specific species management and control information is provided elsewhere. Check the website link provided to check for future updates. The last update for this fact sheet is September, 2004.

NATIVE RANGE: Japan, Korea, China, Malaysia and India

DESCRIPTION: Japanese stilt grass, also known as Nepalese browntop, is an annual plant in the grass family (Poaceae).

Photo: Chris Evans, The Univ. of Georgia, www.invasive.org.

It has a sprawling habit and grows slowly through the summer months, ultimately reaching heights of 2 to 3 1/2 ft. (6-10 dm.).

Photo: James H. Miller, USDA Forest Service, www.invasive.org

The leaves are pale green, lance-shaped, asymmetrical, 1-3 in. (3-8 cm.) long, and have a distinctive shiny midrib.

Photo: David J. Moorhead, The Univ. of Georgia, www.invasive.org.

Slender stalks of tiny flowers are produced in late summer (August - September). The fruits or achenes mature soon after flowering and the plant dies back completely by late fall.

ECOLOGICAL THREAT: Japanese stilt grass is especially well adapted to low light conditions. It threatens native plants and natural habitats in open to shady, and moist to dry locations.

Photo: Chris Evans, The Univ. of Georgia, www.invasive.org.

Stilt grass spreads to form extensive patches, displacing native species that are not able to compete with it. Where white-tail deer are over-abundant, they may facilitate its invasion by feeding on native plant species and avoiding stilt grass.

DISTRIBUTION IN THE UNITED STATES: Japanese stilt grass has been reported to be invasive in natural areas in fourteen eastern states (Connecticut, Delaware, Georgia, Indiana, Kentucky, Maryland, North Carolina, New Jersey, New York, Pennsylvania, Tennessee, Virginia, Wisconsin, West Virginia) and Washington, D.C. Click here to see a distribution map.

HABITAT IN THE UNITED STATES: Stilt grass occurs in a wide variety of habitats including moist ground of open woods, floodplain forests, wetlands, uplands, fields, thickets, paths, clearings, roadsides, ditches, utility corridors, and gardens. It readily invades areas subject to regular mowing, tilling, foot traffic, and other soil disturbing activities. Stilt grass appears to prefer moist, acidic to neutral soils that are high in nitrogen.

BACKGROUND: Introduced into Tennessee around 1919, stilt grass may have accidentally escaped as a result of its use as a packing material for porcelain.

BIOLOGY & SPREAD: Japanese stilt grass is a colonial species that spreads by rooting at stem nodes that touch the ground. Stilt grass reproduces exclusively by seed. Individual plants may produce 100 to 1,000 seeds that fall close to the parent plant. Seed may be carried further by water currents during heavy rains or moved in contaminated hay, soil, or potted plants, and on footwear. Stilt grass seed remains viable in the soil for five or more years and germinates readily.

For more information on the management of Japanese stilt grass, please contact:

Art Gover, Penn State University, LMRC, Orchard Rd., University Park, PA 16802; (814) 863-1184; aeg2@psu.edu.
Fred Yelverton, Box 7620, NCSU Campus Raleigh, NC 27695-7620, (919) 515-5639 (Fred_Yelverton@ncsu.edu).
National Invasive Species Information Center, http://www.invasivespeciesinfo.gov
Nonnative Invasive Plants of Southern Forests, http://www.invasive.org/eastern/srs/
Southeast Exotic Pest Plant Council - Invasive Plant Manual. www.se-eppc.org.
The Nature Conservancy Invasive Species Initiative, http://tncweeds.ucdavis.edu/esadocs.html
Virginia Natural Heritage Program Fact Sheet-Japanese stiltgrass; http://www.dcr.virginia.gov/dnh/invlist.htm

AUTHOR: Jil M. Swearingen, U.S. National Park Service, Washington, DC.

REVIEWERS: Nancy Benton, Gwendolyn Thunhorst.

REFERENCES:
Barden, Lawrence. 1987. Invasion of Microstegium vimineum (Poaceae), an exotic, annual, shade-tolerant, C-4 grass, into a North Carolina floodplain. The American Midland Naturalist 118 (1):40-45.
Barden, Lawrence. 1991. Element Stewardship Abstract: Microstegium vimineum. The Nature Conservancy.
Fairbrothers, D. E. and J.R. Gray. 1972. Microstegium vimineum (Trin.) A. Camus (Gramineae) in the United States. Bulletin of the Torrey Botanical Club 99:97-100.
Hunt, D. M. and Robert E. Zaremba. 1992. The northeastward spread of Microstegium vimineum (Poaceae) into New York and adjacent states. Rhodora 94:167- 170.
LaFleur, A. 1996. Invasive plant information sheet: Japanese stilt grass. The Nature Conservancy, Connecticut Chapter Connecticut, Hartford, CT.
Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS-62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 pp.
Redman, Donnell E. 1995. Distribution and habitat types for Nepal microstegium [Microstegium vimineum (Trin.) Camus] in Maryland and the District of Columbia. Castanea 60(3): 270-275.
Rhoads, A.F. and T.A Block. 2000.The Plants of Pennsylvania, An Illustrated Manual. University of Pennsylvania Press. 1061 pp.
Swearingen, J. 2004. WeedUS: Database of Invasive Plants of Natural Areas in the U.S. Plant Conservation Alliance. http://www.nps.gov/plants/alien
USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?2964 (01 September 2004).

Plant Conservation Alliance, Alien Plant Working Group.

Management and Control Information

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