A perennial shrub, it usually grows to 30–100 cm tall and wide. The leaves are 1–4 cm long, greyish tomentose. The flowers are pinkish-purple (lavender-coloured), produced on spikes 2–3 cm long at the top of slender leafless stems 10–30 cm long; each flower is subtended by a bract 4–8 mm long. At the top of the spike are a number of much larger, sterile bracts (no flowers between them), 10–50 mm long and bright lavender purple (rarely white).