Field Guide

A biennial plant with bristly hairs and usually with single stems, viper’s bugloss can grow 2½ feet tall. The flowers are pink in bud, blue to ultramarine later. The protruding stamens are pink.

Even without its flowers, or its fruits that resemble miniature oranges, common horse gentian is notable for its opposite leaves, which are broadly fused together at the bases and almost appear as a single leaf with a stem going through it.

Horse nettle is a native perennial with spiny stems and leaves, white to purplish flowers, and toxic fruits that look like tiny yellow tomatoes. It does well in disturbed habitats, and many people consider it a weed.

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.

You may not recognize elephant’s foot as a member of the daisy or sunflower family because it lacks petal-like ray florets. Also, it has unusual, doubly compound flower clusters. And how did it get its name, anyway?

Ox-eye daisy, though familiar, is not native to North America. It was introduced long ago from Eurasia. Common in grassy uplands, pastures, fencerows, and roadsides, it can colonize aggressively in the garden.

Our weediest sneezeweed, bitterweed arrived in Missouri in the late 1800s from its home range in Texas and Louisiana. Like our other heleniums, it has domed disks and yellow, fan-shaped, notched ray florets. Unlike them, the leaves are narrowly linear.

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.

Leaf cup is named for the leafy appendages that wrap around the stem at the bases of the opposite leaves. Part of the sunflower family, leaf cup has about 8 white ray florets surrounding yellow disk florets.