GROWTH HABIT: Perennial, forming dense colonies by adventitious shoots from widely spreading black roots.
LEAVES: Lower leaves are deeply lobed, 2 to 4 inches long; upper leaves entire or serrate, narrow to a sessile base.
STEMS: Erect, openly branched, 18 to 36 inches tall.
FLOWER: Cone-shaped flowering heads are 1/4 to 1/2 inch in diameter, solitary at the tip of leafy branchlets. Flowers are pink to lavender. Many pearly involucral bracts form with rounded or acute papery margins. Flowering occurs from June to September.
ROOTS: Black, deep growing roots which penetrate to a depth of over 8 feet.
OTHER: A native of Eurasia, probably introduced in North America about 1898.