The inflorescences are dense umbels at the top of the main branches. They are bright green at the bases and the stiff, bristly bracts are blue. They are about 4 cm long and 2 cm diameter and the bracts are up to long. The flowers inside are about 2 mm long. The peripheral flowers are sterile and the internal flowers are hermaphroditic. Both types are actinomorphic and pentamerous, with five petals. Flowering occurs in July through September. The flowers are -insect-pollinated. The fruit is a spiny achene about half a centimeter wide.