Herbaceous coastal aquatic plant (height from 50 cm to 150 cm) with a thick, succulent horizontal rhizome.
The leaves are erect, long (up to 1 m long), narrow (up to 1 cm in diameter), flat, faceted only at the base, extending from the very base of the stem.
The leafless stem is straight, higher than the leaves, round, at the top with an umbrella of large pinkish-white flowers (up to 2.5 cm in diameter).
The flowers are regular, with 6 pinkish tepals, 9 stamens and 6 pistils. Blooms in mid-summer.