Centaurea stoebe is a bushy, winter-hardy, upright perennial forb living 3 - 5 years or sometimes longer, with a deep taproot.
Foliage
Rosette leaves bluish green, hairy and covered with shiny specks interspersed with translucent dots, 4-8 in. (10-20 cm) long. The size of the leaves decrease in size above the middle of the stem. They are alternate, spiraling and jutting out and upward. Basal leaves deeply divided into elliptic or linear lobes. Lobes become more slender and fewer on upper leaves.
Flowers
Flowers from June-November. Each branch topped by an egg-shaped flower bud covered with overlapping rows of dry, fringed green bracts with black tips. Bracts eventually part at top to allow a constricted pinkish-to-lavender thistle plume to radiate out and up, 0.75-1 in. (2-2.5 cm) wide and overall about 1 in. (2.5 cm) long.
Fruit
Fruits appear from June-February. Tightly packed seed heads of oblong, brownish, hairy nutlets (achenes), 0.1 in. (3 mm) long, topped by short stubby bristles. A thousand seeds can be produced per plant.
Ecological Threat
Centaurea stoebe rapidly colonizes roadsides and disturbed lands, especially dry sites. It can invade adjacent undisturbed prairies and open forests. A severe invasive species spreading into the South by seeds equipped for dispersal by wind, water, livestock, wildlife, and human activity, with viability in the soil for many years.