Field Guide

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.

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.

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.

Sometimes called beebalm, wild bergamot (or horsemint) is a native mint with a long history as a valued Missouri herb. Some people make tea from it, but most of us enjoy its large, colorful flowers.

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.

A square-stemmed plant with opposite leaves, self-heal bears two-lipped blue, lavender, or violet flowers in a cylindrical head. We have two varieties of self-heal in Missouri, one native and one introduced.

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.

Slender mountain mint has smooth, square stems, opposite, narrow leaves, and dense heads of 2-lipped white (or lavender) flowers. Aromatic and minty, it can be grown at home in the herb garden, and its leaves used for seasoning food.

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.