Last month, Invasive Plant Control, Inc., a contractor with the County, found a single plant of Wavyleaf basketgrass in Donaldson Run Park. The plant was removed and the area was surveyed, but no additional plants were found. It is assumed that the seed may have come into Arlington from a neighboring jurisdiction, perhaps along the Potomac River.
According to the National Park Service, “Wavyleaf basketgrass is highly shade-tolerant and remains green until late fall. Once established, it spreads rapidly and forms a dense carpet layer in the forest understory, crowding out native plants and preventing regeneration of native hardwood tree species. It is believed to be more invasive than Japanese stiltgrass, and is often found growing together in some forested areas. It is most active in moist areas but actively spreads in upland areas as well, and persists during dry periods.”
Early Detection, Rapid Response Program (EDRR), we highlighted Wavyleaf basketgrass, or Oplismenus hirtellus, as the best example of an EDRR Species in Arlington County. An EDRR species is an invasive plant that is not widespread in a particular area and may be able to be eradicated. Wavyleaf basketgrass was first discovered in Maryland in 1996 and has since been found in several counties in Maryland and Virginia. For more information about Wavyleaf basketgrass’ distribution, please check out EDDMapS.
How Can You Help
Residents can get involved by learning identification techniques for Wavyleaf Basketgrass. It is a low-growing, shallow-rooted perennial grass that produces long shoots that branch and root at the lower stem nodes. The leaves are dark green and flat with undulating ripples across the leaf surface (about ½ inch wide by 1½-4 inches long). Wavyleaf basketgrass is relatively easy to identify, but has several similarities to other common invasive plant species in our area, including Japanese stiltgrass and Hairy jointgrass. Hairy jointgrass, or Arthraxon hispidus, is also “wavy” but it has lighter leaves and a more upright growth habit. Hairy jointgrass leaves also completely encircle the stem, unlike Wavyleaf basketgrass.
Survey and Removal
Volunteers can help with surveying and mapping EDRR species in parks throughout the County. One tool for online mapping is the Mid-Atlantic Early Detection Network (MAEDN) App, which can be downloaded for free. The app allows users to access species information and photographs in the field. Additionally, users can input data on the infestation, add photographs and record a GPS point in the report. These reports are then verified by a local expert and are communicated with regional land managers.
If you come across Wavyleaf basketgrass, please contact 703-228-1862. Any possible infestations of this plant should be positively identified and a voucher specimen should be collected. After documentation, the infestation can be hand-pulled. It’s important to remove the species before it goes to seed because the seeds are extremely sticky and can be spread easily.