This summer I've found a lot of stiltgrass in western Pennsylvania.
Japanese stiltgrass (Microstegium vimineum) is a native of Eurasia that grows in both sun and shade. In the 1900s it was used as packing material for shipping porcelain from China to the New World. Inevitably, it took root in Tennessee in 1919 and is now present in 24 states and Puerto Rico. In Pennsylvania it's invasive, especially in the woods.
Though grasses are notoriously difficult to identify, stiltgrass has three characteristics that help you figure it out.
(1) Each leaf has a shiny central rib, as shown above.
(2) The rib is off center on the leaf, easiest to see on the underside.
(3) Unlike native grasses, stiltgrass forms a dense carpet on the forest floor that chokes out all other plants.
When you see dense grass like this, check it for shiny off-center ribs. Watch this video for more identification clues.
This year I've seen stiltgrass at all the bike trails and even in the woods in Schenley Park. It looks like a nice carpet until you realize it's invasive. It's everywhere!
How do you get rid of it?
Deer don't eat it. But goats do. Hmmmm.
(photos by Kate St. John)