The Sweet Sedge is a perennial herb, with a long, indefinite, branched, cylindrical rhizome immersed in the mud, about the thickness of a finger and emitting numerous roots. The erect leaves are yellowish-green, 2 to 3 feet in length, few, all radical, sheathing at their bases (which are pink), swordshaped, narrow and flat, tapering into a long, acute point, the edges entire, but wavy or crimped.
The leaves are much like those of Iris, but may readily be distinguished from these and from all others by the peculiar crimped edges and their aromatic odour when bruised.
The scape or flower-stem arises from the axils of the outer leaves, which it much resembles, but is longer and solid and triangular. From one side, near the middle of its length, projecting upwards at an angle, from the stem, it sends out a solid, cylindrical, blunt spike or spadix, tapering at each end, from 2 to 4 inches in length, often somewhat curved and densely crowded with very small greenish-yellow flowers.
Each tiny flower contains six stamens enclosed in a perianth with six divisions and surrounding a threecelled, oblong ovary with a sessile stigma.
The fruit, which does not ripen in Europe, is a berry, being full of mucus, which falls when ripe into the water or to the ground, and is thus dispersed, but it fruits sparingly everywhere and propagates itself mainly by the rapid growth of its spreading rhizome.