Erect perennial with (10-) 20-50 cm. long scapes, usually in fresh water marshes or water channels, glabrous, somewhat fleshy; plant base looking somewhat bulb-like with dense fibrous roots, but rhizome long, slender. Leaves linear, semi-terete, usually deeply furrowed on upper surface towards the base, usually about half as long as the scapes, 2-3 mm. wide, sheathing at the base; sheath 5-8 cm. long, slightly broader than the blade. Scapes elongating in fruit; racemes 30-80-flowered, terminal, much elongated after flowering, usually 20-30 cm. long in fruit. Flowers c. 3 mm. across. Perianth segments 1.5-2 (—2.5) mm. long, 1-1.5 (—2) mm broad, elliptic-ovate, greenish or whitish with usually purplish margins, glabrous. Stamens about half the length of perianth segments, almost sessile; anthers purplish, 0.5 mm. long. Pedicel stiff, filiform, 3-5 mm long, ascend¬ing, somewhat appressed to the axis in fruit but shorter than it. Fruit linear¬clavate or oblong-linear, tapering towards the base, (6—) 8-10 mm. long, 1 mm broad, ± appressed to the axis, glabrous, separating into three mericarps (each with 1 fertile and 1 sterile carpel together) from below upwards when ripe leaving a triangular axis but mericarps remaining connate with stigma after dehiscence; each mericarp somewhat terete, subulate, tapering-aristate at the base, 1-seeded and 1-loculed; seed nearly as long as the carpel, brown, linear-ellipsoid.