About Carduus pycnocephalus L.
Carduus pycnocephalus L. is a winter annual plant. Its stems grow between 8 inches (20 cm) and 6.6 feet (2.0 m) in height, with a texture ranging from hairless to slightly wooly. It produces multiple spiny-winged stems. The plant forms a basal rosette with a diameter of 10–14 inches (25–36 cm). The rosette holds 4 to 10 lobed basal leaves, each measuring 4–6 inches (10–15 cm) long. The lower surfaces of its stem (cauline) leaves are covered in dense, soft hairs, and spines grow at the tips of the leaf lobes. Its flower heads grow in clusters of 2 to 5. The base of the phyllaries beneath the flower heads is densely covered in loose cobwebby hairs, while the phyllary tips are spiny. The corollas are pink to purple, approximately 1.0–1.4 cm (0.4–0.6 in) long. The plant’s fruits range from brown to gold, and are topped with a bristly pappus covered in tiny barbs.
