Field Guide

Tickseed sunflower has flattened black seeds that attach themselves to clothing and pets via two needlelike awns. In flower, it grows in massive displays in moist bottomlands.

Horseweed looks something like a goldenrod, except that the tiny composite flowers are not yellow. Instead, they are cream-colored and rather drab. In Missouri, this plant is especially associated with disturbed habitats and is a troublesome crop weed.

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.

Named for its resemblance to a European herb that was popular in Medieval times, golden Alexanders is a native Missouri wildflower with bright yellow flowers arranged in umbrella-like clusters.

Full grown, water hemlock looks something like a gigantic Queen Anne's lace, but this common, widespread member of the carrot family is the most toxic plant in North America. All parts are deadly. A piece of root the size of a walnut can kill a cow-sized animal.

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.

Missouri has 276 species in the grass family, including well-known crop plants and our native prairie grasses. Distinguishing between the species can be difficult, but it’s easy to learn some basics about the group.

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.

Instantly recognizable as a type of morning glory, hedge bindweed is common in disturbed habitats and can be a serious agricultural weed, but it is not as problematic as its relative field bindweed.