It has a vertical and extensive root system and milky latex.
Stems are hollow and sparingly to highly branched above.
The lower stem is glabrous to glaucous, and the upper stem and peduncles have glandular-tipped hairs. Leaves are reduced upwards and progressively unlobed. Leaf margins are spinulose and vary from dentate to subentire. The inflorescence is a terminal corymbiform cluster of few to several heads. Heads are 3-5 cm in diameter and each is subtended by 38 to 50 narrow, lanceolate bracts arranged in three imbricate rows.