Bull Thistle (Cirsium vulgare)
A tall biennial or short-lived monocarpic thistle, forming a rosette of leaves and a taproot up to 70 cm long in the first year, and a flowering stem 1–1.5 m tall in the second.
Structure: Bushy clump of spiky leaves in first year
Life Cycle: Biennial
What To Look For: Tall cluster of spiky leaves and stems, eventually bearing large purple blossom
Growth Period: Spring and fall