
Asteraceae (daisies and sunflowers)
Ironweeds are tough, grayish-green, branching perennials known for their fluffy-looking clusters of reddish-purple florets. Flowerheads are very numerous, rose-purple with many florets (to 34) in each head. Bracts at the base of the heads are broad, long-pointed, and spreading. Blooms May-September. Leaves alternate, hairy, lanceolate, sharply pointed at both ends, with short stems and fine teeth, to about 6 inches long.
Similar species: There are 5 Vernonia species in Missouri, and they often hybridize, making identification tricky. This species prefers drier habitats and blooms earlier than the others. The broad, long-pointed, spreading bracts at the base of the flowerheads identify this species.
Height: to 4 or 5 feet.
Occurs in upland prairies, glades, upland forests, sometimes on banks of streams and edges of ponds, also pastures, fencerows, old fields, railroads, roadsides, and other open, disturbed areas. This is by far the most abundant ironweed species in Missouri. Ironweeds are a familiar sight on roadsides and pastures. They often indicate overgrazing, as cattle apparently avoid eating them.
Ironweeds were used medicinally by Native Americans, mostly as pain relievers. Some species of ironweeds are being researched for possible use in modern medicines. Ironweeds are generally unwelcome on pastures, where their bitterness makes them distasteful to cattle.
Although herbivorous mammals such as deer and rabbits apparently find the foliage distasteful, butterflies, bees, and other insects are attracted to the flowers. Goldfinches and other seed-eating birds eat the seeds when they develop in late summer and fall.
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!