A small free-floating plant (0.8-3 cm long) that is green, reddish-green or reddish-purple in colour plants have a main stem with several branches regularly arranged on either side and are usually somewhat triangular in shape. These branches readily fragment from the base, leading to the formation of new plants. Its roots have numerous fine side branches that give them a feathery appearance its tiny overlapping 'leaves' (1-2 mm long) are alternately arranged along the branches and borne in two regular rows.