A biennial or occasionally perennial that forms a basal rosette during the first year of growth and produces a flowering stem during the second year.
Spotted knapweed is primarily a weed of pastures, hayfields, roadsides, and sometimes turfgrass.
The first true leaves are similar but narrow to a petiole. Leaves form a basal rosette during the first year of growth, are deeply lobed, and are approximately 6 inches long. Leaves that are produced on the flowering stems are alternate and finely dissected. Leaf surfaces often have inconspicuous short hairs but leaf margins have more noticeable tough hairs. Flowering stems are slender and wiry, branching, and covered with downy hairs.