Field Guide

Wild onion is edible and is also favored by native-plant gardeners, who enjoy its showy umbels of pink flowers and tolerance of dry, rocky sites. This Ozark species blooms in summer and fall.

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.

In early spring, henbit carpets entire fields with the pinkish-purple of its small flowers. This nonnative mint spreads abundantly but causes few problems. It has shallow roots and fades before crops begin to grow.

Shepherd’s purse is a plant that started in Europe and western Asia and has been introduced nearly worldwide. Like the common dandelion, it has several adaptations that make it a successful colonizer of disturbed soil.

Yellow rocket is a mustard native to Eurasia that was introduced long ago and today is found across North America. The mustard family used to be called the Cruciferae, because of the cross shape formed by the four petals.

Next time you breeze past weedy black mustard on the highway or spot it in a fallow field, think of how important this and other mustards are to the world economy – and to your dinner table.

Square, unbranching stems, opposite leaves, two-lipped flowers, and a mild minty fragrance are clues Ohio horsemint is in the mint family. Tight, rounded flower clusters are stacked atop one another at the stem tips.

At first glance, you might overlook corn salad, except for the large colonies it often forms. The young leaves can be eaten as a salad green, hence the name.

Because each plant disperses a large number of seeds, garlic mustard can outcompete native vegetation for light, moisture, nutrients, soil, and space as it quickly colonizes an area.

Smooth spiderwort is the most common and widely distributed of Missouri's spiderworts. It has slender, straight or zigzag stems. The long, narrow leaves are folded lengthwise and attach to the stem in a thick node. The 3 petals of the triangular flower are blue, rose, purple, lavender, or white.