Rice flatsedge is an erect annual sedge with a fibrous root system. Important identifying characteristics of the sedge include shiny, green ridged leaves and a lack of ligule, auricles, tubers and rhizomes. Seedlings are shiny, without hairs, and distinctly ridged and tougher than most grass seedlings. Leaves may be 3 to 8 mm wide and are dark green and shiny with rough margins toward the leaf tips. A membranous sheath occurs at the leaf base. Triangular stems occur in bunches and can be anywhere from 8 to 24 inches tall. Seedheads may reach 8 inches in length, are open, and are composed of several dense spikes. Individual spikes are, in turn, made up of many goldish brown spikelets that are approximately 5 to 13 mm long and 1 1/2 to 2 mm wide.