Rhizomatous. Stems erect, 30–100 cm, often tufted. Leaves basal and cauline; blades 2–6 mm wide. Inflorescence of 3 to 10 well-separated spikes; the lowest bract greater than the inflorescence. Spikes erect; the uppermost 1 to 3 male, the lower female or androgynous, subsessile to pedunculate below, 12–60 mm long, cylindric. Perigynia ascending, green to tan, obovate, veinless, glabrous, 2–3 mm long with a minute beak. Female scales lanceolate, acute, brown with a pale midstripe, equal to or smaller and narrower than the perigynia. Achene 2-sided, smaller than the perigynium (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
We have varieties aquatilis
(T. Holm) Kukenth.