Yellow Ironweed Verbesina alternifolia

Yellow is the color of late summer in the Ozarks. Yellow Ironweed is one of the many yellow wildflowers blooming along the roads and in the pastures from august to killing frost.

 

Verbesina alternifolia Britton ex Kearney

August to October                                       N                                 Family: Asteraceae

                                                                                                            Tribe: Heliantheae

yellow ironweed flower

Flower: A profusion of yellow flowers top short stems forming a loose head at the top of the plant. Not all of the flowers bloom at the same time. Each flower head has up to 10 bright orange yellow ray flowers sweeping down from the globular mass of yellow tube flowers. These are up to half an inch long and stick out individually.

yellow ironweed side flower

Leaf: The leaves are usually alternate but may be opposite in part or all of the plant. The lower leaves may have a short, winged petiole but upper leaves are sessile. each leaf has a slow taper to the center and a slow taper to a sharp point. The leaf top is darker green than the bottom and begin to take on a yellow tinge as the leaf ages. Both sides have a sandpaper texture.

yellow ironweed leaf

Stem: A single stem grows up to 8 feet tall. The only branches are at the top leading to flowers. The green, ridged stem is winged with white hairs between the ridges and wings.

yellow ironweed under leaf

Root: The perennial roots are fibrous and have stout rhizomes so the plant forms colonies.

yellow ironweed stem

Fruit: The seeds develop inside a cage formed by the remains of the tube flowers. This opens to release the flat, brown seeds with small wings along their sides.

yellow ironweed fruit

Habitat: This plant prefers sunny places but will grow in light shade. It likes good soil with moisture as in lower pastures, along roadside ditches, along streams and bases of bluffs.

 

Yellow Ironweed

yellow ironweed plant

Yellow Ironweed has thick, stiff stems letting it tower over most other plants growing nearby. The stems are tough enough to withstand wind and remain upright. This lets it grow wherever it finds the right soil and moisture level.

The tall stems are popular with various vines. False buckwheat, partridge pea, hog peanut, woodbine, morning glories and more twine themselves around the stems and bind several plants together.

Recognizing this plant is fairly easy not only because of its size but by its flowers. The color is vibrant yellow. The back swept rays are irregular in number and arrangement. The globular crown of long, yellow disk flowers sticking out is totally different from the other aster family members. In those the disk or tube flowers are packed close together. Yellow Ironweed tube flowers are separate individuals.

This plant is determined to bloom and produce seeds. Even when the top is eaten off, the lower leaves send out new flower stalks. These will bloom on plants now only two feet tall. The leaves and stem tips do seem popular with deer.

The leaves are large and feel rough. As the plant blooms into the fall, the leaves take on a yellowish green color. The lowest ones turn yellow and drop off.

Yellow Ironweed forms colonies and seeds itself prolifically. These form yellow clouds of flowers along the roads and in the pastures from late summer into fall until frost kills the plants.