A large, robust, fleshy plant with more or less glabrous slightly glaucous leaves; leaves few, ascending. Petioles widely winged, at least on inner leaves, white on outer leaves, pink on inners. Leaf side-lobes 2-4, patent to somewhat recurved, subdeltoid and subobtuse, entire on distal lobes, proximal lobes with several large teeth on the distal margin, interspersed by single conspicuous narrow acute lobules. Leaves heterophyllous, the outer narrower with a usually entire helmet-shaped end-lobe, typically constricted on each side, the inner shortly and broadly triangular and usually subdivided by single rounded lobules. Involucre massive, cup-shaped, formed of broad, heavy, spreading, greyish-pruinose exterior bracts 4-6 mm wide. Capitulum 45-50 mm in diameter when fully expanded, ligules long with a brownish stripe, stigmas yellow in the fresh condition, but drying darker.  

1. sundbergii is unmistakeable and unlikely to be confused with other species. The massive involucres resemble those of T. subundulatum, but that species has bright red petioles throughout. It has been suggested that the British plants differ from the Scandinavian type, particularly with respect to style colour, and this merits further study.