A grass-like, tussocky herb with upright or strappy leaves, which are usually less than 40 centimetres in length, though do occasionally reach 90 cm. Leaves are smooth, linear, often slightly concave or convex, and green or greyish green in colour. Flowers are creamy yellow and occur in clusters on small flower spikes. Though a small plant, many-flowered mat-rush can produce spectacular floral displays in season. Male and female flowers are carried on separate plants and differ in some characteristics.