Greater knapweed

Height: 30–100 cm (12–40 in.). Stem branching from top, bristly.

Flower: Single flower-like 3–4.5 cm (1.2–1.8 in.) capitula surrounded by involucral bracts. Capitula flowers violet red (occasionally pink or white), ray-florets obliquely funnel-shaped, tip lobed; disc florets tubular. Stamens 5. Pistil of 2 fused carpels. Involucre almost spherical, involucral bracts overlapping in many rows, basal part green, tip roundish, brownish black, ciliately fringed. Capitula solitary, terminating stem branches.

Leaves: Alternate, stalked. Blade dark green, slightly leathery, irregularly 1–2 times lobed (occasionally quite entire), lobes narrow.