Field Guide

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.

The tiny white flowers of this native plant are not very memorable, but the curious, sticky-feeling whorls of narrow leaves and lightweight, 4-sided stems make cleavers unique. And then there’s the tiny, round, “Velcro” covered balls of the seeds, which “stick tight” to your socks!

Hydrilla is probably the worst submersed aquatic weed in America. It harms aquatic communities in small ponds, lakes, and rivers. It hurts our economy by hindering fishing and other recreational uses in large reservoirs. Learn about it and prevent its spread.

“It’s an odd plant,” this rattlesnake master, “with its leaves like yucca, a head like a thistle, and second cousin to the carrot.” That’s how the great prairie writer John Madson summed it up!

Three species of yucca grow wild in Missouri. Spanish bayonet was introduced from the Southwest and has escaped from cultivation, but our two soapweeds are native.

Wood nettle, or stinging nettle, often forms dense stands in bottomland forests, streamsides, and other places. There, canoeists, anglers, and others try to avoid touching its stinging hairs!

Pretty but poisonous, jimsonweed has white goblet-shaped flowers that open around midnight. This native of tropical America was introduced nearly throughout the United States and thrives in disturbed soils.

A biennial plant with bristly hairs and usually with single stems, viper’s bugloss can grow 2½ feet tall. The flowers are pink in bud, blue to ultramarine later. The protruding stamens are pink.

Horse nettle is a native perennial with spiny stems and leaves, white to purplish flowers, and toxic fruits that look like tiny yellow tomatoes. It does well in disturbed habitats, and many people consider it a weed.