2n = 30

Plants to c. 70 cm. tall. Rhizome long, slender. Lvs mostly from base c. 30–100 × 1 cm., ± erect; sheathing base channelled; lamina ± keeled, subrhomboid in T.S.; longitudinal nerves obvious; incomplete cross walls occ., thick, green; tip obtuse. Peduncle c. 2 mm. diam., us. shorter than lvs; lower bracts long, foliaceous. Infl. simple to few-branched; main axis with 1–3 female capitula near base, followed by up to 10 male capitula; lateral axes often with only male, but sts with 1–2 female capitula below; capitula sessile and either strictly axillary or without bracts. Fls white. Male capitula c. 1 cm. diam., fls ∞; stamens c. 3 mm. long, filaments much > per.; anthers 2–3 times as long as broad. Female capitula to 1.5 cm. diam., fls c. 60; per.-scales 4–8, the inner ones smaller; ovary c. 4 mm. long, narrow-fusiform; style short; stigma oval, c. ½ style-length. Fr. c. 6 × 3 mm., sessile, obovoid.