Herbaceous, short-lived perennial, 20-80 cm in height. Mostly upright growth habit with axillary branches at lower nodes. Inflorescence is a spherical head with rose to magenta flowers. Leaves are alternate, trifoliate (with three leaflets), each leaflet 15–30 mm long and 8–15 mm broad, green with a characteristic pale crescent in the outer half of the leaf. The petiole is 1–4 cm long, with two basal stipules, fused to the petiole and abruptly narrowed to a bristle-like point. Stems are hollow and pubescent. Short taproots decompose after the first year, replaced with secondary roots.