Eleocharis mutata (L.) Roem. & Schult.

A robust tufted perennial of similar habit to E. acutangula. Culm often 40-60 cm long or more, 2-4 mm thick, triangular. Leaf sheaths purple or brown, ending in an about 5 mm long, narrow triangular limb with a filiform apex. Spikelet 2.5-5.0 cm long and 3-5 mm wide, similar to that of E. acutangula, but with more numerous and more densely set glumes. Glumes about 4 mm long, orbicular to obovate, more obscurely nerved than E. acutangula; margin with a narrow transparent border and a darker border inside. Perianth of 7 bristles with numerous retrorse barbs, all as long as or longer than the nutlet. Stamens 3. Style with 3 branches. Nutlet 1.5-1.8 mm long (not including the 0.5 mm long appendage) and about 1.3 mm wide, obovate, ending in a crater-like rim with a narrow triangular appendage; surface with longitudinal ribs and weaker transverse bars between these, making the nutlet trabeculate.