Microstegium vimineum, commonly known as Japanese stiltgrass or Nepalese browntop, is an annual grass that is common in a wide variety of habitats and is well adapted to low light levels.
It is native in much of South Asia, East Asia as well as parts of Southeast Asia. It can be found from Iran in the west, east to China, south to the Philippines, and has since moved to the United States.
It typically grows to heights between 40 and 100 cm (1.3 and 3.3 ft) and is capable of rooting at each node. The plant flowers in late summer and produces its seeds in the form of a caryopsis shortly thereafter. It is quite similar to and often grows along with the North American grass Leersia virginica, but L. virginica lacks the distinctive silver stripe on the center of the leaf that is present on Japanese stiltgrass and also flowers one to two months earlier.
The plant was accidentally introduced into the U.S. state of Tennessee around 1919 due to its use as a packing material used to ship porcelain from China. It has spread throughout the Southeastern US and is now found in 26 states.Microstegium most commonly invades along roads, floodplain and other disturbed areas, but will also invade undisturbed habitats .Whitetail deer, which do not browse the grass, may facilitate spread by browsing on native species and thereby reducing competition for the exotic plant. Invasion of Microstegium can reduce growth and flowering of native species, suppress native plant communities, alter and suppress insect communities, slow plant succession and alter nutrient cycling. However, removal of Microstegium can lead to recovery of native plant communities
Microstegium vimineum is a warm season grass which can be controlled with pre-emergent herbicides targeted for crabgrass. Post emergent controls can also be successful, such as Calcium acid methanearsonate 8.4% Ortho "Weed-b-Gon" Crabgrass killer for lawns, which contains 2,4-D, and Acclaim Extra as well. Unless noted, surfactants should be added to herbicides for better control. In addition to herbicides, hand weeding and mowing are among the most successful methods of removal. In order to be effective, mowing must be performed before the plants go to seed.