Erect biennial herb 0.5–2 m high, greyish or whitish tomentose with stellate non-glandular hairs.
Lower leaves with lamina 8–50 cm long, 2.5–14 cm wide, with lamina obovate to elliptic, margins entire or crenate, base tapering into petiole, upper leaves sessile and decurrent on stem.
Racemes simple or branched, dense, 15–100 cm long; 2–7 flowers in each bract; bracts 12–18 mm long; pedicels 1–5 mm long. Sepals 6–12 mm long. Corolla 1.5–3 cm diam., yellow; pubescent outside with numerous glandular dots. Stamens 5, unequal in length, 10–15 mm long; lowest pair of filaments (subsp. thapsus and all Aust. specimens seen) glabrous except ± villous near middle, upper 3 villous; anthers reniform; hairs on filaments colorless.
Capsule broad-ovoid, 7–10 mm long, tomentose.