Field Guide

Compass plant grows to 8 feet tall and has foot-long, deeply cleft leaves at its base. It got its common name because its leaves turn so that the surfaces face east and west to take full advantage of the sun’s rays.

Of Missouri’s six rosinweeds, prairie dock is identified by its large, leathery, unlobed leaves, which are nearly all in a basal whorl. Only a few small leaves grow on the stem.

The bizarre, complicated flowers attract attention! The fruits are edible. Passion flower is a nonwoody vine that climbs via tendrils on trees or other structures. It is native to the southeastern United States, including southern Missouri.

“Infestation” is the term for what teasels are doing in Missouri. Learn to identify these thistlelike plants, and help to control the weedy spread of these tough, prickly invaders.

One of the worst invasive species in the world, Japanese knotweed can thrive in many places and can even damage foundations of buildings — not to mention the harm it causes in natural habitats. Learn to recognize it so you can prevent its spread.

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.

Narrow-leaved vervain is a short, slender perennial with single stems or with upper stems sparingly branched. Its many small flowers are crowded on narrow spikes. The corollas are tubular, deep lavender or purple, with 5 spreading lobes.

Sometimes called wild oregano, dittany, like true oregano, is a member of the mint family and can be used as a culinary herb and in teas. Look for it on dry, wooded slopes in Ozark counties.