Porophyllum ruderale var. macrocephalum (Dc.) Cronquist

Herbs 0.15-1.25 m tall. Leaves with blades 7-25 mm long, 4-13 mm wide; petioles 5-15 mm long. Inflorescences with peduncles 3-4 cm long, strongly clavate-inflated. Heads with involucres 20-22 mm long, 6-10 mm diameter, the bracts streaked with 2-3 vertical rows of elongate oil glands; florets 40-60, the corollas 10-12 mm long, the tube 8-9 mm long, the lobes 1-1.5 mm long, the anthers 1.5-2 mm long. Achenes 11-12 mm long; carpopodium 0.5-1 mm long; pappus 7-9 mm long. Chromosome number n = 11

Can be grown by seedlings.