Stems 45-70 cm tall, slender. Leaves dimorphic; sheathlike leaves basal, 4-9 cm; linear leaves 2-4, slightly longer than scape, 50-75 cm × 2-4 mm, abaxially convex, transverse section semicircular. Male part of spikes 3-6 cm, axis hairy, with 1 bract; female part of spikes separated from male part, 1.5-3 cm, 1-1.5 cm in diam. Male flowers: stamens 1; anthers ca. 1.2 mm. Female flowers with small, brown bracteoles; ovary fusiform to elliptic; stalk 2.5-4 mm; styles ca. 0.5 mm, slender; stigmas lanceolate, ca. 0.7 mm; hairs on stalk swelling at tip, shorter than style. Fruit elliptic.
Sides of channels, swamps, wetlands.