Field Guide

Japanese stiltgrass is an invasive annual grass with thin, pale green, lance-shaped leaves that are 3 inches long. It has spread to nearly every eastern U.S. state. It forms dense patches, displacing and outcompeting native species for nutrients and light.

Missouri’s cattails are all tall wetland plants with narrow, upright leaves emerging from a thick base, and a central stalk bearing a brown, sausage-shaped flower spike.

Even without its flowers, or its fruits that resemble miniature oranges, common horse gentian is notable for its opposite leaves, which are broadly fused together at the bases and almost appear as a single leaf with a stem going through it.

One of our more challenging plants to identify, meadow parsnip looks an awful lot like golden Alexanders. But you can do it! Look closely at the flower clusters and at the edges of the leaves, and then check the seeds.

Causasian bluestem and the closely related yellow bluestem are both aggressive, weedy degraders of pasturelands that escape cultivation and endanger native habitats. Learn more about these Old World grasses, and please don’t plant them!

Johnson grass is a native of the Mediterranean that is invasive in our country. It’s a weed that infests cropland and degrades native ecosystems, and heavy infestations are found in all the major river bottoms of Missouri.

Reed canary grass is native to Europe, Asia, and North America, and it varies quite a bit. Our native Missouri version, for instance, is quite different from the Eurasian type that has been widely introduced — and which has proven to be highly invasive.

Common reed is both native and exotic, but it’s the exotic subspecies that has become an invasive problem. Taking over wetlands with its dense stands, it changes the plant and animal communities and even the way the water flows.

Yellow bluestem is a nonnative, aggressive, weedy degrader of pasturelands that escapes cultivation and endangers native habitats. It blooms in Missouri in late June to July, far earlier than our native bluestems.

The brown, starlike, spreading flowers of climbing milkweed differ from those of other milkweeds, but milky sap, warty pods with silk-tasseled seeds, and the structures in the center of the flowers show its true alliance.