Biennial; stems to 1 m tall, unbranched below the middle, with few ascending branches above, densely cobwebby and finely hairy at first, becoming sparsely hairy to nearly naked as it ages; leaves lance-shaped to nearly linear in outline, to 20 cm, glabrous on both surfaces except the midvein often sparsely long hairy; upper leaves lance-shaped or oblong, clasping, with rounded ear-like lobes at the base, spiny on the margins; flowers yellowish to greenish-yellow; flower heads in clusters of three at the ends of the branches, or occasionally solitary, up to 2 cm wide, subtended by reduced spiny leaves; involucral bracts in several series, outer bracts lance-shaped, spine-tipped, smooth, or faintly cobwebby, margins with yellowish spines. Flowers July to September.