During the rosette phase, teasel develops a large taproot. The taproot may be over 2 feet in length and 1 inch in diameter at the crown. The leaves of cut-leaved teasel are broader and have feathering lobes. Stems are also prickly. Teasel's unique inflorescence makes the plant readily identifiable when flowers or seedheads are present.
Flowers are small and packed in dense, oval-shaped heads.
The flowers are subtended by stiff, spiny bracts that are located terminally on the flowering stems. Cut-leaved teasel usually has white flowers, while common teasel generally has purple flowers. Flowering stems may reach 6-7 feet in height. The two species may hybridize. The common and cut-leaved teasels are European plants introduced to North America in the 1700's.