Introduced annual forb to 65cm tall. Leaves opposite each other, joined at the base with a stem-encircling sheath, 1-7cm long, about 2mm wide, linear, hairy or hairless. Flowers with 5 pink petals with notched tips, apparently solitary at the tops of the stems, actually in dense clusters ('heads') of 2-8 flowers, usually with only one flower open at a time.
Description and photo in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 302