Cirsium vulgare aka Scotch Thistle

Cirsium vulgare is called bull thistle or spear thistle. It belongs to the daisy family, Asteraceae. Its native range spans Europe, Siberia, and the Arabian Peninsula. It also includes northwest Africa, Britain, and Ireland. The plant has become naturalized in North America. It grows in fields, meadows, roadsides, and disturbed ground. It can form thick stands that crowd out native plants.

This fast-growing biennial forms a leaf rosette in year one. A tall, branching flower stem rises in year two. Garden plants reach about 3.3–4.9 feet [1–1.5 metres]. North Carolina State reports a broader range of 2–5 feet [0.6–1.5 metres]. Plants spread about 0.3–1.6 feet [0.1–0.5 metres]. The stout green stems have white hairs and dark purple veins. Deeply cut leaves bear stiff spines along their edges. Stem leaves grow in an alternate pattern and clasp the stem. Their upper sides have stiff hairs; softer white hairs grow below.

Pink to purple flower heads open from June to September. Heads grow alone or in small groups of two or three. Each head holds many narrow, tube-shaped disc florets. The surrounding bracts carry sharp spines with yellow tips. Small, flat brown fruits each hold one seed. A feathery pappus helps the wind carry seeds away. Bees and butterflies feed on nectar, and hummingbirds visit the flowers. Songbirds eat the seeds and use their tufts in nests.

Bull thistle needs full sun and prefers moist, well-drained soil. It also grows in dry soil and accepts many soil types. These include sand, loam, clay, and chalk. It tolerates acid, neutral, and alkaline conditions. Sources list USDA zones 3–8 and UK hardiness H7. It has few reported pest or disease problems. Deer tend to leave it alone. Its flowers and seeds have value in wildlife gardens and meadows. Yet it is invasive in North Carolina and noxious in many US areas. Removing spent heads before seed forms helps limit its spread.

Several parts have food uses, including roots, peeled stems, and flower receptacles. Leaves, flowers, and seeds are also listed as edible. Roots and stems are best gathered before flowering. The roots have a mild, starchy taste with some bitterness. Cooking improves their texture. Sharp spines pose a handling hazard; heavy gloves protect the hands. Harvest sites should be free from herbicide treatment. Stem fibre has been used for paper, and seed down for tinder. Recorded folk remedies include poultices, but these records do not establish medical benefit.