Field Guide

Large stands of wind-pollinated giant ragweed commonly form in disturbed areas, causing late-summer misery in the form of hay fever for many Missourians.

The purplish or brownish disk florets of purple-headed sneezeweed set it apart from our other sneezeweeds, whose centers are yellow. Look for it in moist, open areas, mostly in the southern half of the state.

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.

Common ground cherry is closely related to the tomatillo, which you’ve probably seen in the grocery store or had in a delicious salsa verde at a Mexican restaurant. The fruits of ground cherry are edible, too.

You can find small colonies of lance-leaved loosestrife nearly throughout the state. It has showy but nodding yellow flowers and opposite, closely spaced, lanceolate or ovate leaves.

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.

Autumn sneezeweed is a late-blooming perennial with conspicuously winged stems. The flowerheads have yellow, domed disks. The ray flowers are fan-shaped, yellow, and notched.

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.