Carex limosa has a large rhizome and hairy roots. It produces a stem which is generally just under half a meter in height and has a few basal leaves which are long and threadlike. The tip of the stem is often occupied by a staminate spikelet, and below this hang one or more nodding pistillate spikelets. Some spikelets may have both male and female parts, however. Each fruit is a few millimeters long and spade-shaped.