Introduced annual forb to 60cm tall. Leaves opposite each other, the bases united and encircling the stem, 1-5.5cm long, 2-15mm wide, flat, sticky-hairy, with hairy edges. Flowers pink, tubular, with five feeply forked lobes, in raceme-like groups at the tops of the stems, each flower subtended by a leaf-like bract. The flowers only open at night.
Short 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 305