6 August 2026
Have you seen this plant? Its wavy leaves are nothing like the plants I’m used to in Pennsylvania so I was surprised when I saw it at Bear Run Nature Reserve in late May. Was it a new wildflower? No!
This is wavyleaf basketgrass, an extremely invasive plant that is just starting to take hold in Pennsylvania. This month the Pennsylvania iMapInvasives Program is holding a statewide blitz to find it so we can beat it back before it covers the state. I learned about it on The Allegheny Front.
Wavyleaf basketgrass (Oplismenus undulatifolius) doesn’t look very grassy, but it’s a perennial grass native to Eurasia. It spreads in North America by hitchhiking on people and animals that are moving through the forest.
Where did this invader start and where is it now?
Wavyleaf basketgrass was first found in North America in Howard County, Maryland in 1996 and spread quickly into connected natural areas and other Maryland counties. By 2004 (8 years) it had crossed into Virginia in Shenandoah National Park and Fraser Reserve. In 2016 (20 years) it was identified in Pennsylvania for the first time. This year, 2026, it was found firmly established in Smith County (east) Texas. This stuff travels!
And it is under-reported. Here’s the “Listed as Invasive” map.
By now it’s been documented in 8 Pennsylvania counties.
Some counties won’t ever see wavyleaf basketgrass because it prefers moist, shady environments. It takes root in our forested natural areas, the places we’ve saved because they are so unique, places like Bear Run. It ultimately covers the forest floor similar to Japanese stiltgrass. Ironically wavyleaf basketgrass has been found growing under Japanese stiltgrass.
How it Spreads:
Wavyleaf basketgrass seeds are expert hitchhikers. They attach to you, your gear, your dog, wildlife, and of course, deer. Click here for a photo of a dog covered in seeds from the Virginia Native Plant Society website.
If you encounter this invader, be sure to clean it off your gear. If you don’t, the seeds will drop off at your next hiking location and you will unintentionally spread the problem.
Report wavyleaf basketgrass in Pennsylvania in August 2026.
On the Allegheny Front’s A new invasive plant threatens Pennsylvania forests you’ll learn how to identify the plant and where to connect with the statewide blitz. Once you know what it looks like, here’s the form for Reporting Wavyleaf Basketgrass in Pennsylvania.
And here’s why we care right now.
Once a population has become established, complete eradication from a site has proven to be extremely difficult due to a long-lived perennial life cycle, a long seed germination season (April–November), and considerable seed mobility of the species.
— Wikipedia: Wavyleaf basketgrass, invasive