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How to Identify Japanese Stiltgrass

Japanese Stiltgrass, Microstegium vimineum, is an invasive, warm season annual grass. It can be found in shady, moist environments like the understory of forests and along waterways, but it can also establish in sunnier and drier areas. It is a weak-stemmed grass with short, broad leaves that taper at their base and tip. They have a silvery midrib that is slightly off-center and hairs near the leaf base. It has a short membranous ligule that's kind of hard to see.

This grass has a long period of development. It starts to grow in the early spring but waits until late summer or early fall to flower. Its flowers are discreet and easy to miss. It produces a raceme inflorescence with finger-like collections of spikelets.

This video is part of the Grasses at a Glance series by Natural Resources, Environment, and Energy Educator Erin Garrett, University of Illinois Extension. Explore the playlist. Read our blog Grasses at a Glance.