Field Guide

Ironweeds are tough, grayish-green, branching plants known for their fluffy-looking clusters of reddish-purple florets. They are a familiar sight on roadsides and pastures. Identify western ironweed by the bracts at the base of the flowerheads.

Spotted knapweed is an invasive plant that outcompetes native communities, takes over pastureland, and even beats back invasive sericea lespedeza! It has arrived in our state. Let’s prevent its spread.

An invasive native of Eurasia that is spreading in Missouri, musk thistle is a plant you should know. Learn how to tell the difference between our native thistles and these bad guys.

Bull thistle is a weedy introduction from Europe, found statewide. To tell it from our other thistles, note its stems with spiny-margined wings, and its leaves with the upper surface strongly roughened with stiff, spiny bristles.

Tall thistle is a native thistle that can grow to be 10 feet tall! To identify it, notice its leaves, which are unlobed (though they may be wavy or have only shallow, broad lobes), are felty-hairy beneath, and have prickles only along the edges.

Canada thistle is a native to Eurasia and arrived on our continent probably before the Revolutionary War — most likely mixed in agricultural seed. A bad weed of crop fields and rangeland farther north, it causes problems in Missouri, too.

“Infestation” is the term for what teasels are doing in Missouri. Learn to identify these thistlelike plants, and help to control the weedy spread of these tough, prickly invaders.

White heath aster is one of Missouri's most widespread and weedy native asters. It grows in uplands, bottomlands, and nearly all habitats in between. It has a shrubby, wide-branching habit, and the stem leaves are thin and needlelike.

Native to North America, Europe, and Asia, yarrow has been used for medicine and magic for millennia. This aromatic plant has fine, hairy, fernlike leaves and flat-topped clusters of little white flowers.