Centaurea biebersteinii DC.
Synonym: Centaurea stoebe L. ssp. micranthos (Gugler) Hayek
Spotted knapweed is an herbaceous biennial or perennial plant that invades open areas throughout most of the United States. A basal rosette of deeply lobed leaves is produced the first year. Flowering stems are 8-50 inches tall and branched. Stem leaves are alternate and may be slightly lobed or linear. Flowers are purple to pink in color and occur on small flower heads. Spotted knapweed invades a wide variety of habitats including pastures, open forests, prairies, meadows, old fields, and disturbed areas. Spotted knapweed threatens savannas, grasslands, sand dunes and prairies.
Spotted knapweed has been reported in the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) database in the following 6 Indiana counties of Fountain, Jefferson, Kosciusko, Monroe, Porter, and Pulaski.