Description
Potentially Misidentified Species- Leersia virginica (Virginia Cutgrass) is a native species (Brown and Brown 1984).
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Plantae | Magnoliophyta | Liliopsida | Cyperales | Poaceae | Microstegium |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1931 | Established | Expanding | Introduced | Boundary Resident | East Asia | East Asia | Agriculture(Packing Material) |
History of Spread
Microstegium vimineum (Nepal Grass; Nepalese Browntop; Japanese Stiltgrass), native to Asia, was first collected on a streambank near Knoxville TN in 1919. It spread rapidly, and was known from 14 states by 1972 (Fairbrothers and Gray 1972). At present, it is found in 19 states, from FL-TX to NY-CT (Natural Resources Conservation Service 2001).
In the Chesapeake Bay region, it was first collected on a beach of the James River, at City Point near Richmond VA in 1931 (Fairbrothers and Gray 1972; U.S. National Herbarium collections). While M. vimineum is most abundant in upland wooded habatiats (Redman 1996), it was reported from VA tidal swamps by Rheinhardt (1993), from 'moist soil of riverbank' on the Rappahannock River (1968), below Fredericksburg, from the Wicomico River on the Eastern Shore of MD (1968) and from upper intertidal marshes at Otter Point Creek (Pasternack et al. 2000). In the 1980s and 1990s, a great surge in abundance of this grass was noted in the region, with numerous records in every MD county (Redman 1996). It was found throughout the upper elevations of the tidal swamp at Theodore Roosevelt Island, Potomac, DC (Fofonoff, personal observations).
History References- Fairbrothers and Gray 1972; Natural Resources Conservation Service 2001; Pasternack et al. 2000; Redman 1996; Rheinhardt 1993; U.S. National Herbarium collections
Invasion Comments
Vector(s) of Introduction- The most likely vector for the introduction of this plant to North America was rice-straw, used as packing material for goods shipped from Asia (Fairbrothers and Gray 1972). Since the first Chesapeake record was near the port of Richmond VA, packing-material is a likely vector for introdction of M. vimineum into the Chesapeake watershed.
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | ||||
| Salinity (‰) | 0.0 | 0.0 | ||
| Oxygen | ||||
| pH | ||||
| Salinity Range | fresh-oligo |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | ||
| Typical Adult Size (mm) | ||
| Maximum Adult Size (mm) | ||
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
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| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Microstegium vimineum (Nepal Grass) is abundant and rapidly spreading in the Chesapeake Bay watershed (Redman 1996), as well as the rest of the Northeast (Fairbrothers and Gray 1972; Natural Resources Conservation Service 2001). The extent of its occurrence and impacts in tidal wetlands is unclear. As an invader primarily in woodlands, parks, and natural areas, its economic impact may be largely aesthetic. The wide drooping leaves are attractive, but the extensive monospecific stands replace more diverse wildflower communities (Virginia Department of Conservation and Recreation 2000).
References- Fairbrothers and Gray 1972; Redman 1996; Natural Resources Conservation Service 2001; Virginia Department of Conservation and Recreation 2000
Economic Impacts Outside of Chesapeake Bay
Microstegium vimineum (Nepal Grass) is abundant and rapidly spreading in the the Northeast (Fairbrothers and Gray 1972; Hunt and Zaremba 2001; Natural Resources Conservation Service 2001). The extent of its occurrence and impacts in tidal wetlands is unclear. As an invader primarily in woodlands, parks, and natural areas, its economic impact may be largely aesthetic. The wide drooping leaves are attractive, but the extensive monospecific stands replace more diverse wildflower communities (Virgininia Department of Conservation and Recreation 2000).
References- Fairbrothers and Gray 1972; Hunt and Zaremba 2001; Natural Resources Conservation Service 2001; Virginia Department of Conservation and Recreation 2000
Ecological Impacts on Chesapeake Native Species
Microstegium vimineum (Nepal Grass) is abundant and rapidly spreading in the Chesapeake Bay watershed (Redman 1996), as well as the rest of the Northeast (Fairbrothers and Gray 1972; Natural Resources Conservation Service 2001). The extent of its occurrence and impacts in tidal wetlands is unclear.
Competition- Microstegium vimineum is ranked as higly invasive on state plant lists for DE (Delaware Natural Heritage Program 1999), MD (Cooley 1993), and VA (Virginia Department of Conservation and Recreation 1999). It often forms dense, monospecific stands which crowd out native plants in woodlands (Hunt and Zaremba 1993; Virginia Department of Conservation and Recreation 2000). However, in tidal wetlands, it appears to be confined to the uppermost margins (Pasternack et al. 2000).
Habitat Change- Microstegium vimineum's dense stands may degrade habitat for ground-nesting birds, while favoring rodents likely to prey on eggs (Nature Conservancy 2000).
References- Cooley 1993; Delaware Natural Heritage Program 1999; Fairbrothers and Gray 1972; Hunt and Zaremba 1993; Natural Resources Conservation Service 2001; Pasternack et al. 2000; Redman 1996; Tu 2000; Virginia Department of Conservation and Recreation 2000;
Ecological Impacts on Other Chesapeake Non-Native Species
Microstegium vimineum (Nepal Grass) is abundant and rapidly spreading in the Chesapeake Bay watershed (Redman 1996), as well as the rest of the Northeast (Fairbrothers and Gray 1972; Natural Resources Conservation Service 2001). The extent of its occurrence and impacts in tidal wetlands is unclear.
Competition- M. vimineum is likely to compete with other introduced plants with similar habitat preferences (e.g. Polygonum cespitosum, Asian Ladies-thumb), but this is not documented.
Habitat Change- Dense stands of M. vimineum are likely to affect habitat of introduced biota (particularly rodents) as well as native ones.
References- Fairbrothers and Gray 1972; Redman 1996; Natural Resources Conservation Service 2001
References
Brown, Melvin L.; Brown, Russell G. (1984) Herbaceous Plants of Maryland, , College Park. Pp.Cooley, Gene (1993) Invasive exotic plants that threaten native species and natural habitats in Maryland., , Annapolis MD. Pp.
1998 Non-native plant species in Delaware. http://www.dnrec.statede.us/iw/weeds.htm
Fairbrothers, D. E.; Gray, J. R. (1972) Microstegium vimineum (Trin.) A. Camus (Graminae) in the United States, Bulletin of the Torrey Botanical Club 99: 97-100
Harvill, A. M.; Bradley, Ted R.; Stevens, Charles E.; Wieboldt, Thomas F.; Ware, Donna M. E.; Ogle, Douglas W.; Ramsey, Gwynn W.; Fleming, Gary P. (1992) Atlas of the Virginia Flora, , Burkeville, VA. Pp.
Hitchcock, A. S.; Chase, Agnes (1950) Manual of Grasses of the United States., In: (Eds.) . , Washington, D.C.. Pp.
Hunt, D. M.; Zaremba, Robert E. (1992) The northeastward spread of Microstegium vimineum (Poaceae) into New York and adjacent states, Rhodora 94: 167-170
1997-2024 USDA PLANTS Database.. Onine databse
Pasternack, Gregory B.; Hilgartner, William B.; Brush, Grace S. (2000) Biogeomorphology of an upper Chesapeake Bay river-mouth tidal freshwater marsh, Wetlands 20: 520-537
Redman, Donnell E. (1995) Distribution and Habitat types for Nepal Microstegium [Microstegium vimineum (Trin.) Camus] in Maryland and the District of Columbia, Castanea 60: 270-275
Rheinhardt, R. D. (1991) Vegetation ecology of tidal freshwater swamps of the lower Chesapeake Bay U.S.A., , . Pp.
Rheinhardt, Rick (1992) Multivariate analysis of vegetation patterns in tidal freshwater swamps of lower Chesapeake Bay, U.S.A., Bulletin of the Torrey Botanical Club 119: 192-207
Tu, Mandy (2000) Japanese stilt grass, Nepalese browntop, chinese packing grass, In: (Eds.) Element Stewardship Abstract for Microstegium vimineum. , . Pp. 1-8
1999 Invasive Alien Plant Species of Virginia. http://www.state.va.us/~dcr/dnh/invlist.htm